Nov 97 Challenge

Volume Number: 13 (1997)
Issue Number: 11
Column Tag: Programmer's Challenge

by Bob Boonstra, Westford, MA

## Pente®

Reaching once again into the closet where we store board games, I found the game of Pente®, The board physically resembles the board used in GO, but the game strategies are simpler. Pente® is played by two players who alternate placing stones on a 19x19 grid. The objective is to win the game by getting five or more stones in a row or, alternatively, by capturing five or more pairs of your opponent's stones. Your Challenge is to write code that will play the game of Pente® and accumulate the most points (described below) in the minimum time. The prototype for the code you should write is:

```typedef struct Capture {
Point stone1;
Point stone2;
} Capture;

void InitPente(
long boardHalfSize        /* e.g., 9 for a 19x19 board */
/* all coordinates between -boardHalfSize
and +boardHalfSize */
);

void Pente(
Point opponentsMove,    /* your opponent moved here */
Boolean playingFirst,    /* ignore opponentMove */
Point *yourMove,        /* return your move here */
Capture claimCaptures[],  /* return coordinates of captured pairs here */
long *numCaptures,      /* return number of claimCaptures here */
Boolean *claimVictory    /* return true if you claim victory with this move */
);

void TermPente(void);        /* deallocate any dynamic storage */```

Captures take place by bracketing two adjacent stones of your opponents. Given the position

`---BWW---`

... Black can capture the two White stones by playing ...

`---BWWB--`

... after which the two White stones are removed ...

`---B B--`

Captures can occur horizontally, vertically, or diagonally. Note that no capture occurs if White moves into the unoccupied square below:

`---BW-B--`

## Three Months Ago Winner

Congratulations to Peter Lewis (Perth, Australia) for submitting the winning entry to the Stratego Challenge. Peter's entry was a convincing winner in a tournament of the 5 entries submitted. The Stratego tournament consisted of 80 games, with each entry playing against each other entry 8 times, 4 times playing first and 4 times playing second. Peter's entry plays a very good game of Stratego, as evidenced by the fact that it won 30 of the 32 games it played. His algorithm, described in the commentary at the beginning of his code, includes aggressively attempting to capture weaker pieces, exploring with low ranking pieces of his own, running away from stronger pieces, exchanging pieces of equal rank, and advancing toward unknown pieces. Of the 30 games Peter's entry won, 10 were won by capturing the opponent's flag, and 19 were won by eliminating all of the pieces that the opponent could move. (The remaining win resulted from resignation of the opponent.) Several of the entries used delaying tactics in an attempt to take advantage of the scoring rules and force their opponent to earn negative points for a win. As discussed on the Challenge mailing list, I cut off games where one player took longer than 20 seconds, declared a tie, and awarded points (sometimes negative points) to each player. The table below lists the tournament results and point totals for each entry. The number in parentheses after the entrant's name is the total number of Challenge points earned in all Challenges to date prior to this one.

```Name               Wins         Points     Code    Data     Language
Peter Lewis (37)    30          296.62    13436     310       C++
Dennis Jones        13           86.75     8632     414        C
Randy Boring (39)    5           58.68     5724     618        C
Ernst Munter (286)   9           29.45    12044    4072       C++
Tom Saxton (10)      7          -51.69     7320     460        C
```

## Top 20 Contestants

Here are the Top Contestants for the Programmer's Challenge. The numbers below include points awarded over the 24 most recent contests, including points earned by this month's entrants.

```  Rank       Name       Points    Rank         Name           Points
1.    Munter, Ernst     200      11.   Antoniewicz, Andy      24
2.    Gregg, Xan         63      12.   Picao, Miguel Cruz     21
3.    Lewis, Peter       57      13.       Day, Mark          20
4.    Cooper, Greg       54      14.    Higgins, Charles      20
5.    Boring, Randy      41      15.     Studer, Thomas       20
6.    Lengyel, Eric      40      16.       Saxton, Tom        17
7.    Mallett, Jeff      30      17.      Gundrum, Eric       15
8.    Murphy, ACC        30      18.        Hart, Alan        14
9.    Nicolle, Ludovic   28      19     O'Connor, Turlough    14
10.   Larsson, Gustav   27      20.       Karsh, Bill        12
```

There are three ways to earn points: (1) scoring in the top 5 of any Challenge, (2) being the first person to find a bug in a published winning solution or, (3) being the first person to suggest a Challenge that I use. The points you can win are:

```1st place   20 points      5th place              2 points
2nd place   10 points      finding bug            2 points
3rd place    7 points      suggesting Challenge    2 points
4th place    4 points
```

Here is Peter's winning solution:

### Challenge.cp

```#define ASSERTIONS 0
#define DEBUG_RULES 0

#include Timer.h
#include stdlib.h
#include string.h

#include "Challenge.h"

/*
Author: Peter N Lewis

Assumptions:
Only time we spend thinking is counted against out 10 seconds (not time
in GetMove/ReportMove)
[Actually, this assumption is not valid, but Peter won anyway. --Bob]

Method:
Basically we keep track of the board and what we know and what they know.
Each opponent piece has a bit map associated with it describing what pieces
it could be. As we see more pieces, the bit map is culled. If the piece
moves, the bomb & flag bits are removed. If we've seen all Scouts
(for example), then the Scout bit is removed from all remaining pieces. If
all but one bit is remvoed, then we know what the piece is.

At each turn, we simply apply a sequence of actions (listed below) and
take the first action that works. It does very little in the way of
lookahead (it plans out a path, but doesn't remember it and doesn't take
it to account any movement by the opposition)

It keeps a CRC of recent board positions (since the last strike) and doesn't
replay any boards (we want to win, not draw!).

If we exceed 10 seconds thinking time, we resign. Not that this is particularly
likely, in the games I tried, it spend less than half a second total.

Optimizations:
None.

Comment:
It actually plays a half decent game! The end game is not as good as I'd
like, but time is up!
*/

/*
USE SPY
If our spy is next to their 1, kill it

DEFEND AGAINST SPY
if we have seen the spy, ignore this case

If an unknown piece is next to the 1, then run, attack, have another piece attack,
or ignore depending on a table

ATTACK WEAKER
If a known piece is next to a weaker known piece, attack it except if it places
that piece in a dangerous location

EXPLORE ATTACK
If a 6,7,9 is next to an unknown piece, attack it

RETREAT
If a known piece is next to a stronger known piece, run away (preferably
towards something that can kill it or if it's lowly, towards an unknown piece)

SCOUT

ATTACK DISTANT
If a known piece is distant, but a clear path leads a slightly better piece
towards it, advance the better piece (includes miners)

EXPLORE DISTANT
Try exploring (advance lowly pieces towards unknown pieces)

ATTACK KNOWN WITH SAME DISTANT
If a known piece can be attacked by a known identical piece, attack it

FIND FLAG
When few unmoved pieces remain, start assuming they are bombs/flags

MOVE FORWARD
Move any piece we can forward

MOVE
Move any piece we can

RESIGN
Give up
*/

#if ASSERTIONS

static void Assert( short must )
{
if ( !must ) {
DebugStr( "\pAssert failed!\n" );
}
}

#else

#define Assert( must )

#endif

enum {
kEmpty = kFlag+1,
kWater,
kMoved,        // fake rank for moved pieces
};

enum {
kNoColor = 0
};

enum {
kNoNothing = 0x00001FFE,
kStationaryBits = ((1 << kBomb) | (1 << kFlag))
};

enum {
kRepeatedBoards = 1000
};

typedef struct Square {
PlayerColor color;
PieceRank rank;
UInt32 possibilities;
} Square;

typedef Square OurBoard[kBoardSize][kBoardSize];

typedef int Counts[kFlag+1];

typedef UInt32 BoardPossibilities[kBoardSize][kBoardSize];

typedef struct Storage {
UInt32 total_time;
UInt32 extra_time;
OurBoard board;
Counts our_pieces;
Counts their_pieces;
Boolean do_getmove;
Boolean victory;
Square blankSquare;
PlayerColor playerColor;
PlayerColor theirColor;
BoardPossibilities dangers;
BoardPossibilities known_dangers;
UInt32 repeated_board[kRepeatedBoards];
UInt32 repeated_board_count;
} Storage, *StoragePtr;

static char *board_setup[4] = {
// 1 = Marshal, ..., 9 = Scout, : = Spy, ; = Bomb, < = Flag
"8;<;67;7;7",
"48;3862;89",
"6359954865",
"997159:499",
};

static char *start_piece_counts = "0112344458161";

static int dR[4] = { 1, 0, -1, 0 };
static int dC[4] = { 0, -1, 0, 1 };

#if ASSERTIONS

AssertValidBoard
static void AssertValidBoard( StoragePtr storage )
{
int piece;
int count1 = 0;
int count2 = 0;
int row, col;

for ( piece = kMarshall; piece <= kFlag; piece++ ) {
count1 += storage->their_pieces[piece];
}

for ( row = 0; row < kBoardSize; row++ ) {
for( col = 0; col < kBoardSize; col++ ) {
if ( storage->board[row][col].color == storage->theirColor
&& storage->board[row][col].rank == kUnknown ) {
count2++;
}
}
}

Assert( count1 == count2 );
}

#else

#define AssertValidBoard( storage )

#endif

PositionPieces
void PositionPieces(
void *privStorage,        /* 1MB of preinitialized storage for your use */
PlayerColor playerColor,    /* you play red or blue, with red playing first */
Board *theBoard            /* provide the initial position of your pieces */
)
{
StoragePtr storage = (StoragePtr) privStorage;
int row, our_row, their_row, col, board_col;
PlayerColor theirColor;
int piece;
Boolean reverse = (TickCount() & 1) != 0;

Assert( strlen(board_setup[0]) == kBoardSize );
Assert( strlen(board_setup[1]) == kBoardSize );
Assert( strlen(board_setup[2]) == kBoardSize );
Assert( strlen(board_setup[3]) == kBoardSize );

for ( row = 0; row <= 3; row++ ) {
if ( playerColor == kRed ) {
our_row = row;
their_row = (kBoardSize-1)-row;
theirColor = kBlue;
} else {
their_row = row;
our_row = (kBoardSize-1)-row;
theirColor = kRed;
}
for ( col = 0; col < 10; col++ ) {
board_col = reverse ? (kBoardSize-1) - col : col;
(*theBoard)[our_row][col].thePieceRank = (PieceRank)
(board_setup[row][board_col] - '0');
(*theBoard)[our_row][col].thePieceColor = playerColor;

storage->board[our_row][col].color = playerColor;
storage->board[our_row][col].rank =
(*theBoard)[our_row][col].thePieceRank;
storage->board[our_row][col].possibilities = kNoNothing;

storage->board[their_row][col].color = theirColor;
storage->board[their_row][col].rank = kUnknown;
storage->board[their_row][col].possibilities = kNoNothing;
}
}

for ( row = 4; row <= 5; row++ ) {
for( col = 0; col < kBoardSize; col++ ) {
storage->board[row][col].color = (PlayerColor)kNoColor;
storage->board[row][col].rank =
(PieceRank) ((col/2 % 2 == 1) ? kWater : kEmpty);
storage->board[row][col].possibilities = 0;
}
}

for ( piece = kMarshall; piece <= kFlag; piece++ ) {
storage->our_pieces[piece] =
start_piece_counts[piece] - '0';
storage->their_pieces[piece] =
start_piece_counts[piece] - '0';
}

storage->do_getmove = (playerColor == kBlue);
storage->victory = false;
storage->blankSquare = storage->board[4][0];
storage->playerColor = playerColor;
storage->theirColor = playerColor == kRed ? kBlue : kRed;
storage->repeated_board_count = 0;

AssertValidBoard( storage );
}

Learn
static void Learn( StoragePtr storage, Boolean them,
int row, int col, PieceRank rank )
{
Boolean gotall;
PlayerColor thiscolor;
int r, c;

if ( storage->board[row][col].rank == kUnknown ) {

if ( rank == kMoved ) {
UInt32 possibilities =
storage->board[row][col].possibilities;
possibilities &= ~kStationaryBits;

if ( (possibilities & (possibilities-1)) == 0 ) {
// only one bit on! Now we know!
int newrank;
newrank = 0;
while ( (possibilities & 1) == 0 ) {
possibilities >>= 1;
newrank++;
}
rank = (PieceRank)newrank;
} else {
storage->board[row][col].possibilities = possibilities;
}
}

if ( rank != kMoved ) {
storage->board[row][col].rank = rank;
storage->board[row][col].possibilities = (1 << rank);
if ( them ) {
gotall = --storage->their_pieces[rank] == 0;
} else {
gotall = --storage->our_pieces[rank] == 0;
}
if ( gotall ) {
thiscolor = storage->board[row][col].color;
for ( r = 0; r < kBoardSize; r++ ) {
for ( c = 0; c < kBoardSize; c++ ) {
if ( storage->board[r][c].rank == kUnknown
&& storage->board[r][c].color == thiscolor ) {
UInt32 possibilities =
storage->board[r][c].possibilities;
possibilities &= ~ (1 << rank);
storage->board[r][c].possibilities = possibilities;
if ( (possibilities & (possibilities-1)) == 0 ) {
// only one bit on!
int newrank;
newrank = 0;
while ( (possibilities & 1) == 0 ) {
possibilities >>= 1;
newrank++;
}
Learn( storage, them, r, c, (PieceRank)newrank );
}
}
}
}
}
}
} else {
Assert( rank == kMoved ||
storage->board[row][col].rank == rank );
}
}

HandleTheirMove
static void HandleTheirMove( StoragePtr storage,
GetOpponentMove GetMove )
{
PiecePosition moveFrom;
PiecePosition moveTo;
Boolean moveStrike;
MoveResult moveResult;
UnsignedWide start, finish;

Microseconds( &start );
(*GetMove)( &moveFrom,&moveTo, &moveStrike,&moveResult );
Microseconds( &finish );
storage->extra_time += finish.lo - start.lo;

Assert( moveResult.legalMove );
// They must have made a legal move or we would not be called
Assert( !moveResult.victory );
// If they won we would not be called
if ( moveStrike ) {
Learn( storage, true, moveFrom.row, moveFrom.col,
moveResult.rankOfAttacker.thePieceRank );
Learn( storage, false, moveTo.row, moveTo.col,
moveResult.rankOfDefender.thePieceRank );
if ( moveResult.attackerRemoved &&
moveResult.defenderRemoved ) {
storage->board[moveFrom.row][moveFrom.col] =
storage->blankSquare;
storage->board[moveTo.row][moveTo.col] =
storage->blankSquare;
} else if ( moveResult.attackerRemoved ) {
if (storage->board[moveTo.row][moveTo.col].rank == kBomb) {
storage->board[moveFrom.row][moveFrom.col] =
storage->blankSquare;
} else {
storage->board[moveFrom.row][moveFrom.col] =
storage->board[moveTo.row][moveTo.col];
storage->board[moveTo.row][moveTo.col] =
storage->blankSquare;
}
} else {
Assert( moveResult.defenderRemoved );
storage->board[moveTo.row][moveTo.col] =
storage->board[moveFrom.row][moveFrom.col];
storage->board[moveFrom.row][moveFrom.col] =
storage->blankSquare;
}
} else {
storage->board[moveTo.row][moveTo.col] =
storage->board[moveFrom.row][moveFrom.col];
storage->board[moveFrom.row][moveFrom.col] =
storage->blankSquare;
if ( abs(moveTo.row - moveFrom.row) +
abs(moveTo.col - moveFrom.col) > 1 ) {
Learn( storage, true, moveTo.row, moveTo.col, kScout );
} else {
Learn( storage, true, moveTo.row, moveTo.col,
(PieceRank)kMoved );
}
}

AssertValidBoard( storage );
}

FindPiece
static Boolean FindPiece( StoragePtr storage, PlayerColor color,
PieceRank rank, int *row, int *col )
{
int r, c;

for ( r = 0; r < kBoardSize; r++ ) {
for( c = 0; c < kBoardSize; c++ ) {
if ( storage->board[r][c].color == color
&& storage->board[r][c].rank == rank ) {
*row = r;
*col = c;
return true;
}
}
}
return false;
}

IsOnBoardWeak
static Boolean IsOnBoardWeak( int row, int col )
{
return  0 <= row && row < kBoardSize &&
0 <= col && col < kBoardSize;
}

IsOnBoard
static Boolean IsOnBoard( int row, int col )
{
if (   0 <= row && row < kBoardSize &&
0 <= col && col < kBoardSize ) {
if ( row <= 3 || row >= 6 ) {
return true;
}
if ( col <= 1 || col >= 8 ) {
return true;
}
if ( 4 <= col && col <= 5 ) {
return true;
}
}
return false;
}

IsColorPiece
static Boolean IsColorPiece( StoragePtr storage,
int row, int col, PlayerColor color )
{
Assert( IsOnBoardWeak( row, col ) );
return storage->board[row][col].color == color;
}

IsOurPiece
static Boolean IsOurPiece( StoragePtr storage, int row, int col )
{
Assert( IsOnBoardWeak( row, col ) );
return storage->board[row][col].color == storage->playerColor;
}

IsTheirPiece
static Boolean IsTheirPiece( StoragePtr storage,
int row, int col )
{
Assert( IsOnBoardWeak( row, col ) );
return storage->board[row][col].color == storage->theirColor;
}

IsUnknownPiece
static Boolean IsUnknownPiece( StoragePtr storage,
int row, int col )
{
Assert( IsOnBoardWeak( row, col ) );
return storage->board[row][col].rank == kUnknown;
}

IsRankPiece
static Boolean IsRankPiece( StoragePtr storage,
int row, int col, PieceRank rank )
{
Assert( IsOnBoardWeak( row, col ) );
return storage->board[row][col].rank == rank;
}

IsEmptySquare
static Boolean IsEmptySquare( StoragePtr storage,
int row, int col )
{
Assert( IsOnBoardWeak( row, col ) );
return storage->board[row][col].rank == (PieceRank)kEmpty;
}

IsWaterSquare
static Boolean IsWaterSquare( StoragePtr storage,
int row, int col )
{
Assert( IsOnBoardWeak( row, col ) );
return storage->board[row][col].rank == (PieceRank)kWater;
}

IsLowlyRank
static Boolean IsLowlyRank( PieceRank rank )
{
return kCaptain <= rank && rank <= kScout && rank != kMiner;
}

IsLowlyPiece
static Boolean IsLowlyPiece( StoragePtr storage,
int row, int col )
{
Assert( IsOnBoard( row, col ) );
return IsLowlyRank( storage->board[row][col].rank );
}

IsMovedPiece
static Boolean IsMovedPiece( StoragePtr storage,
int row, int col )
{
Assert( IsOnBoard( row, col ) );
return (storage->board[row][col].possibilities &
kStationaryBits) == 0;
}

IsRevealedPiece
static Boolean IsRevealedPiece( StoragePtr storage,
int row, int col )
{
Assert( IsOnBoard( row, col ) );
Assert( IsOurPiece( storage, row, col ) );
UInt32 possibilities = storage->board[row][col].possibilities;
return ( (possibilities & (possibilities-1)) == 0 );
}

PlayerColor color, int row, int col )
{
int d;
int unknowns = 0;

for ( d = 0; d < 4; d++ ) {
int r = row + dR[d];
int c = col + dC[d];

if ( IsOnBoard( r, c ) && IsColorPiece( storage, r, c,           color )
&& IsUnknownPiece( storage, r, c ) ) {
unknowns++;
}
}

return unknowns;
}

static char *defend_spy_table = "RARROAOORARRRARRXAXAOAOOXAXAXAXA";
// Run/Attack/Other/Nothing, >1 unknown:other:danger:moved

LowlyCanAttack
static Boolean LowlyCanAttack( StoragePtr storage, int row,
int col, int *otherRow, int *otherCol )
{
for ( int d = 0; d < 4; d++ ) {
int r = row + dR[d];
int c = col + dC[d];

if ( IsOnBoard( r, c )
&& IsOurPiece( storage, r, c )
&& IsLowlyPiece( storage, r, c ) ) {
*otherRow = r;
*otherCol = c;
return true;
}
}
return false;
}

UpdateDangerPossibilities
static void UpdateDangerPossibilities( StoragePtr storage )
{
int row, col;

for ( row = 0; row < kBoardSize; row++ ) {
for( col = 0; col < kBoardSize; col++ ) {
storage->dangers[row][col] = 0;
storage->known_dangers[row][col] = 0;
}
}
for ( row = 0; row < kBoardSize; row++ ) {
for( col = 0; col < kBoardSize; col++ ) {
if ( IsTheirPiece( storage, row, col ) ) {
UInt32 possibilities =
(storage->board[row][col].possibilities &
~kStationaryBits);
UInt32 known_possibilities = 0;

if ( storage->board[row][col].rank != kUnknown ) {
known_possibilities = possibilities;
}

for ( int d = 0; d < 4; d++ ) {
int r = row + dR[d];
int c = col + dC[d];

if ( IsOnBoard( r, c ) ) {
storage->dangers[r][c] |= possibilities;
storage->known_dangers[r][c] |= known_possibilities;
}
}
}
}
}
}

GetDangerPossibilities
static UInt32 GetDangerPossibilities( StoragePtr storage,
int row, int col )
{
Assert( IsOnBoard( row, col ) );
return storage->dangers[row][col];
}

PossibilitiesCouldKill
static Boolean PossibilitiesCouldKill( PieceRank rank,
UInt32 possibilities )
{
if ( (possibilities & ~kStationaryBits) == 0 ) {
return false;
}

switch ( rank ) {
case kFlag:
return true;
case kBomb:
return (possibilities & (1 << kMiner)) != 0;
case kMarshall:
return (possibilities & ((1 << kMarshall) + (1<< kSpy)))
!= 0;
default:
return (possibilities & ((1 << (rank+1)) - 1)) != 0;
}
}

PossibilitiesCouldKillSafely
static Boolean PossibilitiesCouldKillSafely( PieceRank rank,
UInt32 possibilities )
{
if ( (possibilities & ~kStationaryBits) == 0 ) {
return false;
}

switch ( rank ) {
case kFlag:
return true;
case kBomb:
return (possibilities & (1 << kMiner)) != 0;
case kMarshall:
return (possibilities & ((1<< kSpy))) != 0;
default:
return (possibilities & ((1 << rank) - 1)) != 0;
}
}

WillKillPossibilities
static Boolean WillKillPossibilities( PieceRank rank,
UInt32 possibilities )
{
Assert( possibilities != 0 );

switch ( rank ) {
case kFlag:
return false;
case kBomb:
return false;
case kMiner:
return (possibilities & ~((1 << kScout) + (1 << kBomb) +
(1 << kFlag))) == 0;
case kSpy:
return (possibilities & ~(1 << kMarshall)) == 0;
default:
return (possibilities & (((1 << (rank + 1)) - 1) +
(1 << kBomb))) == 0;
}
}

WillKillOrSuicidePossibilities
static Boolean WillKillOrSuicidePossibilities( PieceRank rank,
UInt32 possibilities )
{
Assert( possibilities != 0 );

switch ( rank ) {
case kFlag:
return false;
case kBomb:
return false;
case kMiner:
return (possibilities & ~((1 << kScout) + (1 << kMiner) +
(1 << kBomb) + (1 << kFlag))) == 0;
case kSpy:
return (possibilities & ~((1 << kMarshall) + (1 << kSpy)))
== 0;
default:
return (possibilities & (((1 << rank) - 1) + (1 << kBomb)))
== 0;
}
}

WillPossibilitiesKill
static Boolean WillPossibilitiesKill( UInt32 possibilities,
PieceRank rank )
{
Assert( possibilities != 0 );
possibilities &= ~kStationaryBits;
if ( possibilities == 0 ) {
return false;
}

switch ( rank ) {
case kFlag:
return true;
case kBomb:
return possibilities == (1 << kMiner);
default:
return (possibilities & ~((1 << (rank+1))-1)) == 0;
}
}

FindSafeSquare
static Boolean FindSafeSquare( StoragePtr storage, int row,
int col, int *safeRow, int *safeCol )
{
Assert( IsOnBoard( row, col ) );

PieceRank rank = storage->board[row][col].rank;
int doff = (storage->playerColor == kBlue ? 0 : 2);
// Try backwards first

for ( int d = 0; d < 4; d++ ) {
int dr = dR[(d + doff) % 4];
int dc = dC[(d + doff) % 4];
int r = row + dr;
int c = col + dc;

while ( IsOnBoard( r, c ) &&
IsEmptySquare( storage, r, c ) ) {
if ( !PossibilitiesCouldKill( rank,
GetDangerPossibilities( storage, r, c ) ) ) {
*safeRow = r;
*safeCol = c;
return true;
}
if ( rank != kScout ) {
break;
}
r += dr;
c += dc;
}
}
return false;
}

CountEnemies
static void CountEnemies( StoragePtr storage, int row, int col,
int *knowns, int *unknowns )
{
*knowns = 0;
*unknowns = 0;

for ( int d = 0; d < 4; d++ ) {
int r = row + dR[d];
int c = col + dC[d];

if ( IsOnBoard( r, c ) && IsTheirPiece( storage, r, c ) ) {
if ( storage->board[r][c].rank == kUnknown ) {
*unknowns += 1;
} else {
*knowns += 1;
}
}
}
}

/*
static Boolean CanRun( StoragePtr storage, int row, int col, int *runRow, int *runCol )
{
for ( int d = 0; d < 4; d++ ) {
int r = row +
dR[(d + (storage->playerColor == kBlue ? 0 : 2)) % 4];
// Try backwards first
int c = col +
dC[(d + (storage->playerColor == kBlue ? 0 : 2)) % 4];

if ( IsOnBoard( r, c ) &&
(storage->board[r][c].rank == kEmpty) ) {
*runRow = r;
*runCol = c;
return true;
}
}
return false;
}
*/

FindSafePath
static Boolean FindSafePath( StoragePtr storage,
Boolean very_safe, Boolean suicide_ok, int from_row,
int from_col, int to_row, int to_col, int *best_path,
int *first_row, int *first_col )
{
Assert( IsOurPiece( storage, from_row, from_col ) );

PieceRank rank = storage->board[from_row][from_col].rank;
BoardPossibilities *dangers =
very_safe ? &storage->dangers : &storage->known_dangers;

if (   abs( from_row - to_row ) +
abs( from_col - to_col ) > *best_path ) {
return false;
}

if ( abs( from_row - to_row ) +
abs( from_col - to_col ) == 1 ) {
*best_path = 0;
*first_row = to_row;
*first_col = to_col;
return true;
}

int path_length_to[kBoardSize][kBoardSize];
PiecePosition que[kBoardSize * kBoardSize];
int que_start = 0;
int que_fin = 0;
int que_next_len = 0;
int current_len = 0;
int row, col;

for ( row = 0; row < kBoardSize; row++ ) {
for( col = 0; col < kBoardSize; col++ ) {
path_length_to[row][col] = -1;
}
}

que[que_fin].row = from_row;
que[que_fin].col = from_col;
path_length_to[from_row][from_col] = 0;
que_fin++;
que_next_len = que_fin;

while ( que_fin > que_start ) {
row = que[que_start].row;
col = que[que_start].col;
que_start++;

for ( int d = 0; d < 4; d++ ) {
int dr = dR[d];
int dc = dC[d];
// scout moves NYI
int r = row + dr;
int c = col + dc;

if ( IsOnBoard( r, c ) && path_length_to[r][c] == -1
&& IsEmptySquare( storage, r, c ) ) {
if ( suicide_ok ?
!PossibilitiesCouldKillSafely( rank, (*dangers)[r][c] )
: !PossibilitiesCouldKill( rank, (*dangers)[r][c]    ) ) {
path_length_to[r][c] = current_len + 1;
if ( abs( to_row - r ) + abs( to_col - c ) == 1 ) {
*best_path = current_len + 1;
while ( current_len > 0 ) {
for ( int d = 0; d < 4; d++ ) {
int backr = r + dR[d];
int backc = c + dC[d];

if ( path_length_to[backr][backc] == current_len ) {
r = backr;
c = backc;
break;
}
}
current_len--;
}
*first_row = r;
*first_col = c;
return true;
}
que[que_fin].row = r;
que[que_fin].col = c;
que_fin++;
} else {
path_length_to[r][c] = 1000; // Cant go here
}
}
}

if ( que_start == que_next_len ) {
que_next_len = que_fin;
current_len++;
}
}

return false;
}

CalcBoardCRC
static UInt32 CalcBoardCRC( StoragePtr storage,
int from_row, int from_col, int to_row, int to_col )
{
Assert( !IsOnBoard( from_row, from_col ) ||
IsOurPiece( storage, from_row, from_col ) );
Assert( !IsOnBoard( to_row, to_col ) ||
IsEmptySquare( storage, to_row, to_col ) );

UInt32 result = 0;

int row, col;
int rankish;

for ( row = 0; row < kBoardSize; row++ ) {
for( col = 0; col < kBoardSize; col++ ) {
if ( row == from_row && col == from_col ) {
rankish = 0;
} else if ( row == to_row && col == to_col ) {
rankish = storage->board[from_row][from_col].rank;
} else if ( IsEmptySquare( storage, row, col ) ||
IsWaterSquare( storage, row, col ) ) {
rankish = 0;
} else if ( IsOurPiece( storage, row, col ) ) {
rankish = storage->board[row][col].rank;
} else {
}
result += rankish; // Hmm, not a very good CRC
result = result * 11 + (result >> 25);
}
}

return result;
}

OKMove
static Boolean OKMove( StoragePtr storage, int from_row, int from_col,
int to_row, int to_col )
{
if ( IsTheirPiece( storage, to_row, to_col ) ) {
return true;
}

UInt32 crc = CalcBoardCRC( storage, from_row, from_col,
to_row, to_col );
long i;
for ( i = 0; i < storage->repeated_board_count; i++ ) {
if ( crc == storage->repeated_board[i] ) {
return false;
}
}
return true;
}

AppendRepeatedBoard
static void AppendRepeatedBoard( StoragePtr storage )
{
UInt32 crc = CalcBoardCRC( storage, -1, -1, -1, -1 );

if ( storage->repeated_board_count == kRepeatedBoards ) {
storage->repeated_board_count--;
BlockMoveData( &storage->repeated_board[1],
&storage->repeated_board[0],
storage->repeated_board_count *
sizeof(storage->repeated_board[0]) );
}
storage->repeated_board[storage->repeated_board_count++] = crc;
}

#if DEBUG_RULES
#define RETURN( x ) DebugStr( x ";g" ); return
#else
#define RETURN( x ) return
#endif

FigureOutOurMove
static void FigureOutOurMove( StoragePtr storage,
PiecePosition *moveFrom, PiecePosition *moveTo )
{
int ourRow, ourCol,theirRow,theirCol,row,col,runRow,runCol;
int rowFirst = storage->playerColor == kRed ?
0 : kBoardSize - 1;
int rowLast = storage->playerColor == kRed ?
kBoardSize - 1 : 0;
int rowAdd = storage->playerColor == kRed ? 1 : -1;
int bestUnknowns;
int bestPath;
int thisPath;

UpdateDangerPossibilities( storage );

// USE SPY
if ( FindPiece( storage, storage->theirColor, kMarshall,
&theirRow, &theirCol )
&& FindPiece( storage, storage->playerColor, kSpy,
&ourRow, &ourCol )
&& abs( theirRow - ourRow ) +
abs( theirCol - ourCol ) == 1 ) {
moveFrom->row = ourRow;
moveFrom->col = ourCol;
moveTo->row = theirRow;
moveTo->col = theirCol;
RETURN( "\pUSE SPY" );
}
```
```// DEFEND AGAINST SPY
if (storage->their_pieces[kSpy] > 0) {
if ( FindPiece( storage, storage->playerColor, kMarshall,
&ourRow, &ourCol ) ) {
storage->theirColor, ourRow, ourCol );

if ( unknowns ) {
char todo = 0; // R = Run, A = Attack, O = Attack with Other
int base_index = 0;
Boolean canrun = FindSafeSquare( storage, ourRow, ourCol,
&runRow, &runCol );
if ( !canrun ) {
base_index += 16;
}
if ( unknowns > 1 ) {
base_index += 8;
}

for ( int d = 0; d < 4; d++ ) {
int r = ourRow + dR[d];
int c = ourCol + dC[d];
int otherRow, otherCol;

if ( IsOnBoard( r, c )
&& IsTheirPiece( storage, r, c )
&& IsUnknownPiece( storage, r, c ) ) {
int index = base_index;
if ( LowlyCanAttack( storage, r, c,
&otherRow, &otherCol ) ) {
index += 4;
}
storage->theirColor, r, c ) > 0 ) {
index += 2;
}
if ( IsMovedPiece( storage, r, c ) ) {
index += 1;
}

if ( defend_spy_table[index] == 'A' ) { // Attack
moveFrom->row = ourRow;
moveFrom->col = ourCol;
moveTo->row = r;
moveTo->col = c;
RETURN( "\pDEFEND AGAINST SPY 1" );
} else if ( defend_spy_table[index] == 'O' ) { // Attack
moveFrom->row = otherRow;
moveFrom->col = otherCol;
moveTo->row = r;
moveTo->col = c;
RETURN( "\pDEFEND AGAINST SPY 2" );
}
}
}

if ( canrun && OKMove( storage, ourRow, ourCol,
runRow, runCol ) ) {
moveFrom->row = ourRow;
moveFrom->col = ourCol;
moveTo->row = runRow;
moveTo->col = runCol;
RETURN( "\pDEFEND AGAINST SPY 3" );
}
// Give up! Next rule...
}
}
}

// ATTACK WEAKER
for ( row = rowFirst; 0 <= row && row < kBoardSize;
for( col = 0; col < kBoardSize; col++ ) {
if ( IsTheirPiece( storage, row, col ) ) {
UInt32 enemy = storage->board[row][col].possibilities;
UInt32 danger = GetDangerPossibilities( storage,
row, col );

int bestDir = -1;
Boolean isBestRevealed = true;
PieceRank bestRank = kUnknown;

for ( int d = 0; d < 4; d++ ) {
int r = row + dR[d];
int c = col + dC[d];

if ( IsOnBoard( r, c ) && IsOurPiece( storage, r, c ) ) {
if ( !PossibilitiesCouldKill(
storage->board[r][c].rank, danger ) ) {
if ( WillKillPossibilities(
storage->board[r][c].rank, enemy ) ) {
Boolean thisRevealed =
IsRevealedPiece( storage, r, c );
if ( isBestRevealed || !thisRevealed ) {
if ( bestDir == -1 ||
(storage->board[r][c].rank > bestRank) ) {
bestDir = d;
bestRank = storage->board[r][c].rank;
isBestRevealed = thisRevealed;
}
}
}
}
}
}
if ( bestDir != -1 ) {
moveFrom->row = row + dR[bestDir];
moveFrom->col = col + dC[bestDir];
moveTo->row = row;
moveTo->col = col;
RETURN( "\pATTACK WEAKER" );
}
}
}
}

// EXPLORE ATTACK
for ( int rnk = kScout; rnk >= kMarshall; rnk-- ) {
PieceRank rank = (PieceRank) rnk;
if ( IsLowlyRank( rank ) ) {

for ( row = rowLast; 0 <= row && row < kBoardSize;
for( col = 0; col < kBoardSize; col++ ) {
if ( IsOurPiece( storage, row, col )
&& IsRankPiece( storage, row, col, rank ) ) {

for ( int d = 0; d < 4; d++ ) {
int r = row + dR[d];
int c = col + dC[d];

if ( IsOnBoard( r, c )
&& IsTheirPiece( storage, r, c )
&& IsRankPiece( storage, r, c, kUnknown ) ) {
moveFrom->row = row;
moveFrom->col = col;
moveTo->row = r;
moveTo->col = c;
RETURN( "\pEXPLORE ATTACK" );
}
}
}
}
}
}
}

// RETREAT
for ( row = rowLast; 0 <= row && row < kBoardSize;
for( col = 0; col < kBoardSize; col++ ) {
if ( IsOurPiece( storage, row, col )
&& IsMovedPiece( storage, row, col ) ) {

for ( int d = 0; d < 4; d++ ) {
int r = row + dR[d];
int c = col + dC[d];

if ( IsOnBoard( r, c )
&& IsTheirPiece( storage, r, c )
&& WillPossibilitiesKill(
storage->board[r][c].possibilities,
storage->board[row][col].rank ) ) {
bestPath = 1000;
for ( int to_row = rowLast; 0 <= to_row &&
to_row < kBoardSize; to_row -= rowAdd ) {
for( int to_col = 0; to_col < kBoardSize; to_col++ ) {
thisPath = bestPath;
if ( IsTheirPiece( storage, to_row, to_col )
&& (IsRankPiece( storage, to_row, to_col,
kUnknown )
|| WillKillPossibilities(
storage->board[row][col].rank,
storage->board[to_row][to_col].possibilities ))
&& FindSafePath( storage, false, true, row, col,
to_row, to_col, &thisPath, &runRow, &runCol )
&& OKMove( storage, row, col, runRow, runCol ) ) {
bestPath = thisPath;
moveFrom->row = row;
moveFrom->col = col;
moveTo->row = runRow;
moveTo->col = runCol;
}
}
}
if ( bestPath < 1000 ) {
RETURN( "\pRETREAT" );
}
}
}
}
}
}

// SCOUT
bestUnknowns = 0;

for ( row = rowLast; 0 <= row && row < kBoardSize;
for( col = 0; col < kBoardSize; col++ ) {
if ( IsOurPiece( storage, row, col )
&& IsRankPiece( storage, row, col, kScout ) ) {
for ( int d = 0; d < 4; d++ ) {
int r = row + dR[d];
int c = col + dC[d];

while ( IsOnBoard( r, c ) &&
IsEmptySquare( storage, r, c ) ) {

int knowns, unknowns;
CountEnemies( storage, r, c, &knowns, &unknowns );
if ( knowns == 0 && unknowns > bestUnknowns &&
OKMove( storage, row, col, r, c ) ) {
bestUnknowns = unknowns;
ourRow = row;
ourCol = col;
runRow = r;
runCol = c;
}
r += dR[d];
c += dC[d];
}
}
}
}
}

if ( bestUnknowns > 0 ) {
moveFrom->row = ourRow;
moveFrom->col = ourCol;
moveTo->row = runRow;
moveTo->col = runCol;
RETURN( "\pSCOUT" );
}

// ATTACK DISTANT

bestPath = 1000;

for ( row = rowFirst; 0 <= row && row < kBoardSize;
for( col = 0; col < kBoardSize; col++ ) {
if ( IsTheirPiece( storage, row, col ) ) {
UInt32 possibilities =
storage->board[row][col].possibilities;
UInt32 danger =
GetDangerPossibilities( storage, row, col );

if ( (possibilities & ((1 << kBomb) | (1 << kMarshall))) !=
((1 << kBomb) | (1 << kMarshall)) ) {
for ( int r = rowFirst; 0 <= r && r < kBoardSize;
for( int c = 0; c < kBoardSize; c++ ) {
if ( IsOurPiece( storage, r, c ) ) {
if ( WillKillPossibilities(
storage->board[r][c].rank, possibilities ) ) {
if ( storage->board[r][c].rank >= kCaptain ||
!PossibilitiesCouldKill(
storage->board[r][c].rank, danger ) ) {
thisPath = bestPath;
if ( FindSafePath( storage, true, false, r, c,
row, col, &thisPath, &runRow, &runCol ) ) {
if ( OKMove( storage, r, c, runRow, runCol ) ) {
bestPath = thisPath;
moveFrom->row = r;
moveFrom->col = c;
moveTo->row = runRow;
moveTo->col = runCol;
}
}
}
}
}
}
}
}

}
}
}

if ( bestPath < 1000 ) {
RETURN( "\pATTACK DISTANT" );
}

// EXPLORE DISTANT

bestPath = 1000;

for ( row = rowFirst; 0 <= row && row < kBoardSize;
for( col = 0; col < kBoardSize; col++ ) {
if ( IsTheirPiece( storage, row, col ) &&
storage->board[row][col].rank == kUnknown ) {

for ( int r = rowFirst; 0 <= r && r < kBoardSize;
for( int c = 0; c < kBoardSize; c++ ) {
if ( IsOurPiece( storage, r, c ) &&
IsLowlyPiece( storage, r, c ) ) {
thisPath = bestPath;
if ( FindSafePath( storage, false, true, r, c,
row, col, &thisPath, &runRow, &runCol ) ) {
if ( OKMove( storage, r, c, runRow, runCol ) ) {
bestPath = thisPath;
moveFrom->row = r;
moveFrom->col = c;
moveTo->row = runRow;
moveTo->col = runCol;
}
}
}
}
}

}
}
}

if ( bestPath < 1000 ) {
RETURN( "\pEXPLORE DISTANT" );
}

// ATTACK KNOWN WITH SAME DISTANT

bestPath = 1000;

for ( row = rowFirst; 0 <= row && row < kBoardSize;
for( col = 0; col < kBoardSize; col++ ) {
if ( IsTheirPiece( storage, row, col ) ) {
UInt32 possibilities =
storage->board[row][col].possibilities;

if ( (possibilities & ((1 << kBomb) | (1 << kMarshall))) !=
((1 << kBomb) | (1 << kMarshall)) ) {
for ( int r = rowFirst; 0 <= r && r < kBoardSize;
for( int c = 0; c < kBoardSize; c++ ) {
if ( IsOurPiece( storage, r, c ) ) {
if ( WillKillOrSuicidePossibilities(
storage->board[r][c].rank, possibilities ) ) {
thisPath = bestPath;
if ( FindSafePath( storage, true, true, r, c,
row, col, &thisPath, &runRow, &runCol ) ) {
if ( OKMove( storage, r, c, runRow, runCol ) ) {
bestPath = thisPath;
moveFrom->row = r;
moveFrom->col = c;
moveTo->row = runRow;
moveTo->col = runCol;
}
}
}
}
}
}
}

}
}
}

if ( bestPath < 1000 ) {
RETURN( "\pATTACK KNOWN WITH SAME DISTANT" );
}

// FIND FLAG
// NYI

// MOVE FORWARD

for ( row = rowLast; 0 <= row && row < kBoardSize; row -= rowAdd ) {
for( col = 0; col < kBoardSize; col++ ) {
if ( IsOurPiece( storage, row, col ) ) {
PieceRank rank = storage->board[row][col].rank;
if ( rank != kBomb && rank != kFlag ) {
int r = row + rowAdd;
if ( IsOnBoard( r, col ) && !IsOurPiece( storage, r, col ) &
& OKMove( storage, row, col, r, col ) ) {
moveFrom->row = row;
moveFrom->col = col;
moveTo->row = r;
moveTo->col = col;
RETURN( "\pMOVE FORWARD" );
}
}
}
}
}

// MOVE

for ( row = rowLast; 0 <= row && row < kBoardSize;
for( col = 0; col < kBoardSize; col++ ) {
if ( IsOurPiece( storage, row, col ) ) {
PieceRank rank = storage->board[row][col].rank;
if ( rank != kBomb && rank != kFlag ) {

for ( int d = 0; d < 4; d++ ) {
int r = row + dR[d];
int c = col + dC[d];

if ( IsOnBoard( r, c ) &&
!IsOurPiece( storage, r, c ) &&
OKMove( storage, row, col, r, c ) ) {
moveFrom->row = row;
moveFrom->col = col;
moveTo->row = r;
moveTo->col = c;
RETURN( "\pMOVE" );
}
}
}
}
}
}

// RESIGN
moveFrom->row = -1;
moveFrom->col = -1;
moveTo->row = -1;
moveTo->col = -1;
RETURN( "\pRESIGN" );

}

HandleOurMove
static void HandleOurMove( StoragePtr storage,
ReportYourMove ReportMove )
{
PiecePosition moveFrom;
PiecePosition moveTo;
Boolean moveStrike;
MoveResult moveResult;
UnsignedWide start, finish;

if ( storage->total_time > 10000000 ) { // Time to give up
// Resign
moveFrom.row = -1;
moveFrom.col = -1;
moveTo.row = -1;
moveTo.col = -1;
} else {
FigureOutOurMove( storage, &moveFrom, &moveTo );
}
if ( IsOnBoard( moveTo.row, moveTo.col ) ) {
moveStrike = storage->board[moveTo.row][moveTo.col].color !=
kNoColor;
} else {
moveStrike = false;
}

Microseconds( &start );
(*ReportMove)( &moveFrom, &moveTo, moveStrike, &moveResult );
Microseconds( &finish );
storage->extra_time += finish.lo - start.lo;

if ( moveResult.victory ) {       // We Win! :-)
storage->victory = true;
} else if ( !moveResult.legalMove ) {   // We Lose! :-(
} else {
if ( moveStrike ) {
storage->repeated_board_count = 0;
Learn( storage, true, moveTo.row, moveTo.col,
moveResult.rankOfDefender.thePieceRank );
Learn( storage, false, moveFrom.row, moveFrom.col,
moveResult.rankOfAttacker.thePieceRank );

if ( moveResult.attackerRemoved &&
moveResult.defenderRemoved ) {
storage->board[moveFrom.row][moveFrom.col] =
storage->blankSquare;
storage->board[moveTo.row][moveTo.col] =
storage->blankSquare;
} else if ( moveResult.attackerRemoved ) {
if ( storage->board[moveTo.row][moveTo.col].rank==kBomb ) {
storage->board[moveFrom.row][moveFrom.col] =
storage->blankSquare;
} else {
storage->board[moveFrom.row][moveFrom.col] =
storage->board[moveTo.row][moveTo.col];
storage->board[moveTo.row][moveTo.col] =
storage->blankSquare;
}
} else {
Assert( moveResult.defenderRemoved );
storage->board[moveTo.row][moveTo.col] =
storage->board[moveFrom.row][moveFrom.col];
storage->board[moveFrom.row][moveFrom.col] =
storage->blankSquare;
}

} else {
if ( abs( moveTo.row - moveFrom.row ) +
abs( moveTo.col - moveFrom.col ) > 1 ) {
Assert( storage->board[moveFrom.row][moveFrom.col].rank ==
kScout );
Learn( storage, false, moveFrom.row, moveFrom.col, kScout);
} else {
Learn( storage, false, moveFrom.row, moveFrom.col,
(PieceRank)kMoved );
}
storage->board[moveTo.row][moveTo.col] =
storage->board[moveFrom.row][moveFrom.col];
storage->board[moveFrom.row][moveFrom.col] =
storage->blankSquare;
}
AppendRepeatedBoard( storage );
}

AssertValidBoard( storage );
}

MakeAMove
Boolean MakeAMove(
void *privStorage,      /* 1MB of storage from PositionPieces */
PlayerColor playerColor,    /* you play red or blue, with red playing first */
GetOpponentMove *GetMove,  /* callback used to find about opponents last move*/
ReportYourMove *ReportMove  /* callback used to make a move */
)
{
StoragePtr storage = (StoragePtr) privStorage;
UnsignedWide start, finish;

storage->extra_time = 0;
Microseconds( &start );

if ( storage->do_getmove ) {
HandleTheirMove( storage, *GetMove );
}
storage->do_getmove = true;

HandleOurMove( storage, *ReportMove );

Microseconds( &finish );
storage->total_time +=
finish.lo - start.lo - storage->extra_time;

return storage->victory;
}
```

### CHALLENGE.H

```#ifndef __LL_CHALLENGE__
#define __LL_CHALLENGE__

#ifdef __cplusplus
extern "C" {
#endif

#define kBoardSize 10

typedef enum { kUnknown=0,
kMarshall=1,kGeneral,kColonel,kMajor,kCaptain,
kLieutenant,kSergeant,kMiner,kScout,kSpy,
kBomb,kFlag
} PieceRank;

typedef enum {kRed=1,kBlue=2} PlayerColor;

typedef struct PieceType {
PieceRank  thePieceRank;     /* rank of a piece */
PlayerColor thePieceColor;    /* color of a piece */
} PieceType;

typedef PieceType Board[kBoardSize][kBoardSize];
/* Used to provide test code with board configuration. Red starts
in rows 0..3, Blue starts in rows 6..9 */
/* Squares [4][2], [4][3], [4][6], [4][7] and
[5][2], [5][3], [5][6], [5][7] are water and cannot
be occupied */

typedef struct PiecePosition {
long row; /* 0..9 */
long col; /* 0..9 */
} PiecePosition;

typedef struct MoveResult {
PieceType rankOfAttacker;
/* after a strike, returns identity of attacker */
PieceType rankOfDefender;
/* after a strike, returns identity of defender */
Boolean attackerRemoved;
/* true after a strike against a piece of equal or greater rank,
or against a bomb when the attacker is not a Miner */
Boolean defenderRemoved;
/* true after a strike by a piece of equal or greater rank,
or against a bomb when the attacker is a Miner,
or against a Marshall by a Spy */
Boolean victory;
/* true after a strike against the Flag */
Boolean legalMove;
/* true unless you
- move into an occupied square, or
- move or strike in a direction other than forward, backward, or sideways, or
- move more than one square (except Scouts), or
- move a Bomb or a Flag,
- move into Water, or
- strike a square not occupied by an opponent, or
- make any other illegal move */
} MoveResult;

void PositionPieces(
void *privStorage,      /* 1MB of preinitialized storage for your use */
PlayerColor playerColor,  /* you play red or blue, with red playing first */
Board *theBoard        /* provide the initial position of your pieces */
);

typedef void (*ReportYourMove)(
/* Callback to inform test code of move and
get results */
PiecePosition *moveFrom,  /* piece you are moving or using to strike */
PiecePosition *moveTo,    /* destination square or square being struck */
Boolean strike,          /* false indicates a move, true indicates a strike */
MoveResult *results      /* returns identity of struck piece and other info */
);

typedef void (*GetOpponentMove)(
/* Callback to get results of opponents last move */
PiecePosition *moveFrom,    /* piece opponent moved or used to strike */
PiecePosition *moveTo,      /* destination square or square struck */
Boolean *strike,           /* false indicates a move, true indicates a strike */
MoveResult *results       /* returns identity of struck piece and other info */
);

Boolean MakeAMove(
void *privStorage,        /* 1MB of storage from PositionPieces */
PlayerColor playerColor,   /* you play red or blue, with red playing first */
GetOpponentMove *GetMove,   /* callback used to find about opponents last move */
ReportYourMove *ReportMove  /* callback used to make a move */
);

#ifdef __cplusplus
}
#endif

#endif                ```

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Audition CC 2018 is available as part of Adobe Creative Cloud for as little as \$19.99/month (or \$9.99/month if you're a previous Audition customer). Adobe Audition CC 2018 empowers you to create and... Read more
Adobe After Effects CC 2018 15.0.1 - Cre...
After Effects CC 2018 is available as part of Adobe Creative Cloud for as little as \$19.99/month (or \$9.99/month if you're a previous After Effects customer). The new, more connected After Effects CC... Read more
Adobe Premiere Pro CC 2018 12.0.1 - Digi...
Premiere Pro CC 2018 is available as part of Adobe Creative Cloud for as little as \$19.99/month (or \$9.99/month if you're a previous Premiere Pro customer). Adobe Premiere Pro CC 2018 lets you edit... Read more
Adobe Photoshop CC 2018 19.1 - Professio...
Photoshop CC 2018 is available as part of Adobe Creative Cloud for as little as \$19.99/month (or \$9.99/month if you're a previous Photoshop customer). Adobe Photoshop CC 2018, the industry standard... Read more
Spotify 1.0.69.336. - Stream music, crea...
Spotify is a streaming music service that gives you on-demand access to millions of songs. Whether you like driving rock, silky R&B, or grandiose classical music, Spotify's massive catalogue puts... Read more
rekordbox 5.1.1.0001 - Professional DJ m...
rekordbox is the best way of preparing and managing your tracks, be it at home, in the studio, or even on the plane! It allows you to import music from other music-management software using the... Read more
Mactracker 7.7.1 - Database of all Mac m...
Mactracker provides detailed information on every Mac computer ever made, including items such as processor speed, memory, optical drives, graphic cards, supported OS X versions, and expansion... Read more

## Latest Forum Discussions

Jydge hints, tips, and tricks - Everythi...
Just released on iOS, Jydge is a prequel to Neon Chrome and is set in the same universe. Not just that, but the games play in pretty similar ways with them both being twin stick shooters full of surprises. As you might expect from a 10tons game,... | Read more »
World of Warships Blitz: A guide to tact...
Ahoy mates! It's time to set out on the high seas for some PvP battles, and ... sorry, actually, World of Warships Blitz has nothing to do with pirates. Let's start over. [Read more] | Read more »
Around the Empire: What have you missed...
Around this time every week we're going to have a look at the comings and goings on the other sites in Steel Media's pocket-gaming empire. We'll round up the very best content you might have missed, so you're always going to be up to date with the... | Read more »
In this part of our Hero Academy 2 guide, we're going to have a look at some of the tactics you're going to need to learn if you want to rise up the ranks. We're going to start off slow, then get more advanced in the next section. [Read more] | Read more »
All the best games on sale for iPhone an...
Another week has flown by. Sometimes it feels like the only truly unstoppable thing is time. Time will make dust of us all. But before it does, we should probably play as many awesome mobile videogames as we can. Am I right, or am I right? [Read... | Read more »
The 7 best games that came out for iPhon...
Well, it's that time of the week. You know what I mean. You know exactly what I mean. It's the time of the week when we take a look at the best games that have landed on the App Store over the past seven days. And there are some real doozies here... | Read more »
Popular MMO Strategy game Lords Mobile i...
Delve into the crowded halls of the Play Store and you’ll find mobile fantasy strategy MMOs-a-plenty. One that’s kicking off the new year in style however is IGG’s Lords Mobile, which has beaten out the fierce competition to receive Google Play’s... | Read more »
Blocky Racing is a funky and fresh new k...
Blocky Racing has zoomed onto the App Store and Google Play this week, bringing with it plenty of classic kart racing shenanigans that will take you straight back to your childhood. If you’ve found yourself hooked on games like Mario Kart or Crash... | Read more »
Cytus II (Games)
Cytus II 1.0.1 Device: iOS Universal Category: Games Price: \$1.99, Version: 1.0.1 (iTunes) Description: "Cytus II" is a music rhythm game created by Rayark Games. It's our fourth rhythm game title, following the footsteps of three... | Read more »
JYDGE (Games)
JYDGE 1.0.0 Device: iOS Universal Category: Games Price: \$4.99, Version: 1.0.0 (iTunes) Description: Build your JYDGE. Enter Edenbyrg. Get out alive. JYDGE is a lawful but awful roguehate top-down shooter where you get to build your... | Read more »

## Price Scanner via MacPrices.net

Where to buy 13″ Apple MacBook Pros for up to...
B&H Photo has 13″ MacBook Pros on sale for \$100 off MSRP. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 13-inch 2.3GHz/128GB Space Gray MacBook Pro (MPXQ2LL/A... Read more
Apple Refurbished 2017 iMacs available starti...
Apple has a full line of Certified Refurbished iMacs available for up to \$350 off original MSRP. Apple’s one-year warranty is standard, and shipping is free. The following models are available: – 27... Read more
Apple offers clearance 2016 13-inch MacBook A...
Apple has Certified Refurbished 2016 13″ MacBook Airs available starting at \$809. An Apple one-year warranty is included with each MacBook, and shipping is free: – 13″ 1.6GHz/8GB/128GB MacBook Air: \$... Read more
Clearance Apple refurbished iMacs available s...
Apple has previous-generation Certified Refurbished 2015 21″ & 27″ iMacs available starting at \$849. Apple’s one-year warranty is standard, and shipping is free. The following models are... Read more
How to save \$150-\$420 on the purchase of a 20...
B&H Photo has 15″ MacBook Pros on sale for up to \$200 off MSRP. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 15″ 2.8GHz Touch Bar MacBook Pro Space Gray (... Read more
How to save \$100-\$180 on the purchase of a 20...
B&H Photo has 13″ MacBook Airs on sale for \$50-\$120 off MSRP. Shipping is free, and B&H charges sales tax for NY & NJ residents only: – 13″ 1.8GHz/128GB MacBook Air (MQD32LL/A): \$899, \$... Read more
Save on Beats: \$30-\$80 off headphones, earpho...
Walmart has Beats by Dr. Dre on sale on their online store for \$30-\$80 off MSRP, depending on the item: – Powerbeats3 Wireless Earphones: \$134, save \$65 – BeatsX Earphones: \$109, save \$40 – Beats... Read more
Deals on clearance 15″ Apple MacBook Pros wit...
B&H Photo has clearance 2016 15″ MacBook Pros available for up to \$800 off original MSRP. Shipping is free, and B&H charges NY & NJ sales tax only: – 15″ 2.7GHz Touch Bar MacBook Pro... Read more
Apple restocked Certified Refurbished 13″ Mac...
Apple has restocked a full line of Certified Refurbished 2017 13″ MacBook Airs starting at \$849. An Apple one-year warranty is included with each MacBook, and shipping is free: – 13″ 1.8GHz/8GB/128GB... Read more
How to find the lowest prices on 2017 Apple M...
Apple has Certified Refurbished 13″ and 15″ 2017 MacBook Pros available for \$200 to \$420 off the cost of new models. Apple’s refurbished prices are the lowest available for each model from any... Read more

## Jobs Board

*Apple* Retail - Multiple Positions - Apple,...
Job Description: Sales Specialist - Retail Customer Service and Sales Transform Apple Store visitors into loyal Apple customers. When customers enter the store, Read more
Product Manager- *Apple* News - Apple (Unit...
# Product Manager- Apple News Job Number: 52399385 Santa Clara Valley, California, United States Posted: 19-Jan-2018 Weekly Hours: 40.00 **Job Summary** The Apple Read more
*Apple* Solutions Consultant - Apple (United...
# Apple Solutions Consultant Job Number: 113384559 Brandon, Florida, United States Posted: 10-Jan-2018 Weekly Hours: 40.00 **Job Summary** Are you passionate about Read more
Security Engineering Coordinator, *Apple* R...
# Security Engineering Coordinator, Apple Retail Job Number: 113237456 Santa Clara Valley, California, United States Posted: 18-Jan-2018 Weekly Hours: 40.00 **Job Read more
*Apple* Data Center Site Selection and Strat...
# Apple Data Center Site Selection and Strategy Research Analyst Job Number: 83708609 Santa Clara Valley, California, United States Posted: 18-Jan-2018 Weekly Hours: Read more