depth search

headers/eval.h

@@ -0,0 +1,4 @@
+#ifndef EVAL_H
+#define EVAL_H
+move *findBest(move* move, size_t size, game* g);
+#endif

headers/types.h

@@ -20,6 +20,7 @@ typedef struct {
 typedef struct {
   int From;
   int To;
+  char Promo;
 } move;
 
 #endif

src/eval.c

@@ -0,0 +1,117 @@
+#include "types.h"
+#include "help.h"
+#include "moves.h"
+#include <stddef.h>
+#include <ctype.h>
+#include <stdio.h>
+
+#define PAWN_VALUE 100
+#define KNIGHT_VALUE 320
+#define BISHOP_VALUE 330
+#define ROOK_VALUE 500
+#define QUEEN_VALUE 900
+#define KING_VALUE 20000
+#define INF 9000000
+#define MAX_DEPTH 3  // Adjustable depth
+
+int evaluateBoard(game *game);
+void makeMove(game *g, move* m);
+int negamax(game *g, int depth, int alpha, int beta, int color);
+
+move *findBest(move* moves, size_t size, game* g){
+  int bestScore = -INF;
+  move *bestMove = moves;
+  int color = g->whiteToMove ? 1 : -1;
+
+  for (int i = 0; i < size; i++) {
+    game gg = *g;
+    makeMove(&gg, &moves[i]);
+    int score = -negamax(&gg, MAX_DEPTH, -INF, INF, -color);
+    if (score > bestScore) {
+      bestScore = score;
+      bestMove = &moves[i];
+      printf("info score cp %d\n", g->whiteToMove ? bestScore : -bestScore);
+    }
+  }
+  return bestMove;
+}
+
+int evaluateBoard(game *game) {
+  int score = 0;
+
+  for (int i = 0; i < 64; ++i) {
+    long long bit = 1LL << i;
+    if (game->white.pawns & bit) score += PAWN_VALUE;
+    else if (game->white.knights & bit) score += KNIGHT_VALUE;
+    else if (game->white.bishops & bit) score += BISHOP_VALUE;
+    else if (game->white.rooks & bit) score += ROOK_VALUE;
+    else if (game->white.queen & bit) score += QUEEN_VALUE;
+    else if (game->white.king & bit) score += KING_VALUE;
+  }
+
+  for (int i = 0; i < 64; ++i) {
+    long long bit = 1LL << i;
+    if (game->black.pawns & bit) score -= PAWN_VALUE;
+    else if (game->black.knights & bit) score -= KNIGHT_VALUE;
+    else if (game->black.bishops & bit) score -= BISHOP_VALUE;
+    else if (game->black.rooks & bit) score -= ROOK_VALUE;
+    else if (game->black.queen & bit) score -= QUEEN_VALUE;
+    else if (game->black.king & bit) score -= KING_VALUE;
+  }
+
+  return score;
+}
+
+void makeMove(game *g, move* m) {
+  //should replace inside of PlayMoves but im lazy
+  long long from_bit = 1LL << m->From;
+  long long to_bit = 1LL << m->To;
+
+  long long *set = findSet(g, from_bit);
+  if (!set)
+    return;
+  *set &= ~from_bit;
+
+  long long *captured = findSet(g, to_bit);
+  if (captured) *captured &= ~to_bit;
+
+  if (m->Promo) {
+    char promoChar = g->whiteToMove ? toupper(m->Promo) : m->Promo;
+    long long *newSet = charToSet(g, promoChar);
+    if (newSet)
+      *newSet |= to_bit;
+  } else {
+    *set |= to_bit;
+  }
+
+  g->whiteToMove = !g->whiteToMove;
+}
+
+int negamax(game *g, int depth, int alpha, int beta, int color) {
+  if (depth == 0)
+    return color * evaluateBoard(g);
+
+  move moves[1500];
+  int cnt = pawnMove(g, moves);
+  cnt += knightMove(g, moves + cnt);
+  cnt += rookMove(g, moves + cnt);
+  cnt += bishopMove(g, moves + cnt);
+  cnt += kingMove(g, moves + cnt);
+  cnt += queenMove(g, moves + cnt);
+
+  if (cnt == 0)
+    return 0;
+
+  int bestValue = -INF;
+  for (int i = 0; i < cnt; i++) {
+    game gg = *g;
+    makeMove(&gg, &moves[i]);
+
+    int value = -negamax(&gg, depth - 1, -beta, -alpha, -color);
+
+    if (value > bestValue) bestValue = value;
+    if (value > alpha) alpha = value;
+    if (alpha >= beta) break;
+  }
+  return bestValue;
+}

src/main.c

@@ -9,6 +9,7 @@
 #include "moves.h"
 #include "types.h"
 #include "help.h"
+#include "eval.h"
 
 #define BUFF_SIZE 4096
 
@@ -27,7 +28,8 @@ int main() {
   char ltz[] = "abcdefgh";
   int cnt = 0;
   while (1) {
-    (void)fgets(line, sizeof(line), stdin);
+    if(!fgets(line, sizeof(line), stdin))
+      return 0;
     size_t len = strlen(line);
     if (len - 1)
       line[len - 1] = '\0';
@@ -55,14 +57,14 @@ int main() {
       printf("readyok\n");
     } else if (!strcmp("go", token)) {
       static move mov[1500];//big dumb buffer
-      int cnt = 0;
+      size_t cnt = 0;
       cnt += pawnMove(g,mov);
       cnt += knightMove(g,(mov+cnt));
       cnt += rookMove(g,(mov+cnt));
       cnt += bishopMove(g,(mov+cnt));
       cnt += kingMove(g,(mov+cnt));
       cnt += queenMove(g,(mov+cnt));
-      move *m = &mov[rand() % cnt];
+      move *m = findBest(mov,cnt,g);
 
       char *end = "";
       int yTo, xTo, yFrom, xFrom;
@@ -72,7 +74,7 @@ int main() {
       yFrom = m->From / 8 + 1;
 
       long long bit = 1LL << m->From;
-      if (((g->whiteToMove && yTo == 8) || (!g->whiteToMove && yTo == 1)) && ((findSet(g,bit) == &g->white.pawns) || (findSet(g,bit) == &g->black.pawns))) {
+      if (m->Promo) {
 	end = "q\n";
       } else {
         end = "\n";

src/moves.c

@@ -12,6 +12,7 @@ int pawnMove(game *g, move *moves) {
   long long pawns = g->whiteToMove ? g->white.pawns : g->black.pawns;
   long long enemy = g->whiteToMove ? fullSet(&g->black) : fullSet(&g->white);
   long long occupied = fullSetBoth(g);
+  long long promo = (0xFFLL) << (g->whiteToMove ? 56 : 0);
 
   int movdir = g->whiteToMove ? 8 : -8;
   int capLeft = g->whiteToMove ? 7 : -9;
@@ -21,25 +22,29 @@ int pawnMove(game *g, move *moves) {
 
   for (int i = 0; i < 64; ++i) {
     long long bit = 1LL << i;
+    char p = 0;
     if (!(pawns & bit))
       continue;
 
     // forword
     int to = i + movdir;
+    p = (promo & (1LL << to)) ? 'q' : 0;
     if (to >= 0 && to < 64 && !(occupied & (1LL << to))) {
-      moves[index++] = (move){.From = i, .To = to};
+      moves[index++] = (move){.From = i, .To = to, .Promo = p};
     }
 
     // left
     to = i + capLeft;
+    p = (promo & (1LL << to)) ? 'q' : 0;
     if (i % 8 > 0 && (to >= 0 && to < 64) && (enemy & (1LL << to))) {
-      moves[index++] = (move){.From = i, .To = to};
+      moves[index++] = (move){.From = i, .To = to, .Promo = p};
     }
 
     // right
     to = i + capRight;
+    p = (promo & (1LL << to)) ? 'q' : 0;
     if (i % 8 < 7 && (to >= 0 && to < 64) && (enemy & (1LL << to))) {
-      moves[index++] = (move){.From = i, .To = to};
+      moves[index++] = (move){.From = i, .To = to, .Promo = p};
     }
   }
   return index;
@@ -77,7 +82,7 @@ int knightMove(game *g, move *moves) {
       if (occupied & destBit)
         continue;
 
-      moves[index++] = (move){.From = i, .To = to};
+      moves[index++] = (move){.From = i, .To = to, .Promo=0};
     }
   }
   return index;
@@ -107,7 +112,7 @@ int rookScan(game *g, move *moves, long long w, long long b) {
       long long lbit = 1LL << to;
       if (occupied & lbit)
         break;
-      moves[index++] = (move){.From = i, .To = to};
+      moves[index++] = (move){.From = i, .To = to, .Promo=0};
       if (occupiedE & lbit)
         break;
     }
@@ -118,7 +123,7 @@ int rookScan(game *g, move *moves, long long w, long long b) {
       long long lbit = 1LL << to;
       if (occupied & lbit)
         break;
-      moves[index++] = (move){.From = i, .To = to};
+      moves[index++] = (move){.From = i, .To = to, .Promo=0};
       if (occupiedE & lbit)
         break;
     }
@@ -129,7 +134,7 @@ int rookScan(game *g, move *moves, long long w, long long b) {
       long long lbit = 1LL << to;
       if (occupied & lbit)
         break;
-      moves[index++] = (move){.From = i, .To = to};
+      moves[index++] = (move){.From = i, .To = to, .Promo=0};
       if (occupiedE & lbit)
         break;
     }
@@ -140,7 +145,7 @@ int rookScan(game *g, move *moves, long long w, long long b) {
       long long lbit = 1LL << to;
       if (occupied & lbit)
         break;
-      moves[index++] = (move){.From = i, .To = to};
+      moves[index++] = (move){.From = i, .To = to, .Promo=0};
       if (occupiedE & lbit)
         break;
     }
@@ -179,7 +184,7 @@ int bishopScan(game *g, move *moves, long long w, long long b) {
 
       if (occupied & lbit)
         break;
-      moves[index++] = (move){.From = i, .To = to};
+      moves[index++] = (move){.From = i, .To = to, .Promo=0};
       if (occupiedE & lbit)
         break;
     }
@@ -196,7 +201,7 @@ int bishopScan(game *g, move *moves, long long w, long long b) {
 
       if (occupied & lbit)
         break;
-      moves[index++] = (move){.From = i, .To = to};
+      moves[index++] = (move){.From = i, .To = to, .Promo=0};
       if (occupiedE & lbit)
         break;
     }
@@ -213,7 +218,7 @@ int bishopScan(game *g, move *moves, long long w, long long b) {
 
       if (occupied & lbit)
         break;
-      moves[index++] = (move){.From = i, .To = to};
+      moves[index++] = (move){.From = i, .To = to, .Promo=0};
       if (occupiedE & lbit)
         break;
     }
@@ -230,7 +235,7 @@ int bishopScan(game *g, move *moves, long long w, long long b) {
 
       if (occupied & lbit)
         break;
-      moves[index++] = (move){.From = i, .To = to};
+      moves[index++] = (move){.From = i, .To = to, .Promo=0};
       if (occupiedE & lbit)
         break;
     }
@@ -272,7 +277,7 @@ int kingMove(game *g, move *moves){
 
       if (toX >= 0 && toX < 8 && toY >= 0 && toY < 8) {
         if (!(occupied & destBit)) {
-          moves[index++] = (move){.From = i, .To = to};
+          moves[index++] = (move){.From = i, .To = to, .Promo=0};
         }
       }
     }