assigment1-18: done up to check (no checkmate)
This commit is contained in:
Claudio Maggioni (maggicl)
parent
a022bf6d0a
commit
635486c9b5
2 changed files with 247 additions and 94 deletions
BIN
assignment1-18/chess
Executable file
BIN
assignment1-18/chess
Executable file
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@ -1,10 +1,38 @@
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// vim: set ts=4 sw=4 et tw=80:
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#include <stdio.h>
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#include "./chessboard.h"
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#include <string.h>
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#include <stdbool.h>
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#include <stdlib.h>
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#include "./chessboard.h"
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#define DEBUG_BUILD
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#ifdef DEBUG_BUILD
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#define DEBUG(...) fprintf(stderr, __VA_ARGS__);
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#else
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#define DEBUG(...) (void) 0;
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#endif
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static inline void cb_move(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col);
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static inline int sign(int n);
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static inline enum player player(struct chessboard* cb, int row, int col);
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static inline bool is_empty(struct chessboard* cb, int row, int col);
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static bool check_empty_paths(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col);
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static bool can_move_pawn(struct chessboard* cb, enum player p,
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int from_row, int from_col, int to_row, int to_col);
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static bool can_move_rook(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col);
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static bool can_move_knight(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col);
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static bool can_move_bishop(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col);
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static bool can_move_queen(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col);
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static bool can_move_king(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col);
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void init_chessboard(struct chessboard * cb) {
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int i;
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@ -65,8 +93,8 @@ void print_chessboard(struct chessboard * cb) {
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}
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inline void cb_move(struct chessboard* cb, int from_row, int from_col, int to_row,
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int to_col) {
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inline void cb_move(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col) {
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cb->position[to_row][to_col] = cb->position[from_row][from_col];
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cb->position[from_row][from_col] = EMPTY;
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}
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@ -79,122 +107,212 @@ inline enum player player(struct chessboard* cb, int row, int col) {
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return cb->position[row][col] < 7 ? WHITE : BLACK;
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}
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inline int sign(int n) {
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return n == 0 ? 0 : (n > 0 ? 1 : -1);
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}
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enum mstatus move_pawn(struct chessboard* cb, enum player p, int from_row,
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int from_col, int to_row, int to_col) {
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bool can_move_pawn(struct chessboard* cb, enum player p,
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int from_row, int from_col, int to_row, int to_col) {
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DEBUG("can_move_pawn: from: row %d col %d to: row %d col %d\n",
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from_row, from_col, to_row, to_col);
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// two forward if in the starting position, no capture is valid
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if (((p == WHITE && from_row == 1 && to_row == 3 &&
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is_empty(cb, 2, from_col)) ||
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(p == BLACK && from_row == 7 && to_row == 5 &&
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is_empty(cb, 6, from_col))) &&
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(p == BLACK && from_row == 6 && to_row == 4 &&
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is_empty(cb, 5, from_col))) &&
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from_col == to_col &&
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is_empty(cb, to_row, to_col)) {
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cb_move(cb, from_row, from_col, to_row, to_col);
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return VALID;
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DEBUG("can_move_pawn: two forward, valid\n");
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return true;
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// one forward, no capture is valid
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} else if (((p == WHITE && to_row - from_row == 1) ||
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(p == BLACK && from_row - to_row == 1)) &&
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from_col == to_col &&
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is_empty(cb, to_row, to_col)) {
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cb_move(cb, from_row, from_col, to_row, to_col);
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return VALID;
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DEBUG("can_move_pawn: one forward no capture, valid\n");
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return true;
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// one forward, one left or right, with capture, is valid
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} else if !(to_row = from_row + (p == WHITE ? 1 : -1) &&
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} else if (to_row == from_row + (p == WHITE ? 1 : -1) &&
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abs(from_col - to_col) == 1 &&
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!is_empty(cb, to_row, to_col) &&
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player(cb, to_row, to_col) != p) {
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cb_move(cb, from_row, from_col, to_row, to_col);
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return VALID;
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!is_empty(cb, to_row, to_col)) {
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DEBUG("can_move_pawn: one forward diagonal capture, valid\n");
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return true;
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} else {
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return INVALID;
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DEBUG("can_move_pawn: move pawn not valid\n");
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return false;
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}
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}
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enum mstatus check_empty_paths(struct chessboard* cb, int from_row,
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int from_col, int to_row, int to_col) {
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int ii = sign!(to_row - from_row), jj = sign(to_col - from_col);
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bool check_empty_paths(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col) {
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int ii = sign(to_row - from_row), jj = sign(to_col - from_col);
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int i = from_row + ii, j = from_col + jj;
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for(; i != to_col || j != to_row; i += ii; j += jj) {
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DEBUG("check_empty_paths: from: row %d col %d, to: row %d col %d, ii: %d,"
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" jj: %d\n", from_row, from_col, to_row, to_col, ii, jj);
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for (; !(i == to_row && j == to_col); i += ii, j += jj) {
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if (!is_empty(cb, i, j)) {
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return INVALID;
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DEBUG("check_empty_paths: position row %d col %d"
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" is occupied\n", i, j);
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return false;
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}
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}
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cb_move(cb, from_row, from_col, to_row, to_col);
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return VALID;
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return true;
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}
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enum mstatus move_rook(struct chessboard* cb, enum player p, int from_row,
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int from_col, int to_row, int to_col) {
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if !(to_row != from_row && to_col != from_col) {
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return INVALID;
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bool can_move_rook(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col) {
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if (to_row != from_row && to_col != from_col) {
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return false;
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}
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return check_empty_paths(cb, from_row, from_col, to_row, to_col);
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}
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enum mstatus move_bishop(struct chessboard* cb, enum player p, int from_row,
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int from_col, int to_row, int to_col) {
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if (from_row - to_row != from_col - to_col || from_row == to_row) {
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return INVALID;
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bool can_move_bishop(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col) {
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if (abs(from_row - to_row) != abs(from_col - to_col)) {
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return false;
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}
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return check_empty_paths(cb, from_row, from_col, to_row, to_col);
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}
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enum mstatus move_queen(struct chessboard* cb, enum player p, int from_row,
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int from_col, int to_row, int to_col) {
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if (!(to_row != from_row && to_col != from_col) &&
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(from_row - to_row != from_col - to_col)) {
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return INVALID;
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}
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return check_empty_paths(cb, from_row, from_col, to_row, to_col);
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bool can_move_queen(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col) {
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return can_move_bishop(cb, from_row, from_col, to_row, to_col) ||
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can_move_rook(cb, from_row, from_col, to_row, to_col);
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}
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enum mstatus move_knight(struct chessboard* cb, enum player p, int from_row,
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int from_col, int to_row, int to_col) {
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if (!(to_row == from_row + 2 && to_col == from_col + 1) &&
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!(to_row == from_row + 2 && to_col == from_col - 1) &&
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!(to_row == from_row - 2 && to_col == from_col + 1) &&
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!(to_row == from_row - 2 && to_col == from_col - 1) &&
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!(to_row == from_row + 1 && to_col == from_col + 2) &&
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!(to_row == from_row - 1 && to_col == from_col + 2) &&
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!(to_row == from_row + 1 && to_col == from_col - 2) &&
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!(to_row == from_row - 1 && to_col == from_col + 2)) {
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return INVALID;
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}
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bool can_move_knight(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col) {
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return (to_row == from_row + 2 && to_col == from_col + 1) ||
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(to_row == from_row + 2 && to_col == from_col - 1) ||
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(to_row == from_row - 2 && to_col == from_col + 1) ||
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(to_row == from_row - 2 && to_col == from_col - 1) ||
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(to_row == from_row + 1 && to_col == from_col + 2) ||
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(to_row == from_row - 1 && to_col == from_col + 2) ||
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(to_row == from_row + 1 && to_col == from_col - 2) ||
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(to_row == from_row - 1 && to_col == from_col + 2);
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}
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cb_move(cb, from_row, from_col, to_row, to_col);
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return VALID;
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)
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bool can_move_king(struct chessboard* cb,
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int from_row, int from_col, int to_row, int to_col) {
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if (abs(to_row - from_row) > 1) {
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DEBUG("can_move_king: row movement too big (from %d to %d)\n", from_row,
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to_row);
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return false;
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}
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if (abs(to_col - from_col) > 1) {
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DEBUG("can_move_king: column movement too big (from %d to %d)\n",
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from_col, to_col);
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return false;
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}
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return true;
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}
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bool can_move(struct chessboard* cb, enum player p,
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int from_row, int from_col, int to_row, int to_col) {
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// try to understand which piece we are moving
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switch (cb->position[from_row][from_col]) {
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case WHITE_PAWN:
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case BLACK_PAWN:
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DEBUG("can_move: moving a pawn\n");
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return can_move_pawn(cb, p, from_row, from_col, to_row, to_col);
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case WHITE_ROOK:
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case BLACK_ROOK:
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DEBUG("can_move: moving a rook\n");
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return can_move_rook(cb, from_row, from_col, to_row, to_col);
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case WHITE_BISHOP:
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case BLACK_BISHOP:
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DEBUG("can_move: moving a bishop\n");
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return can_move_bishop(cb, from_row, from_col, to_row, to_col);
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case WHITE_QUEEN:
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case BLACK_QUEEN:
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DEBUG("can_move: moving a queen\n");
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return can_move_queen(cb, from_row, from_col, to_row, to_col);
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case WHITE_KNIGHT:
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case BLACK_KNIGHT:
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DEBUG("can_move: moving a knight\n");
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return can_move_knight(cb, from_row, from_col, to_row, to_col);
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case WHITE_KING:
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case BLACK_KING:
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DEBUG("can_move: moving a king\n");
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return can_move_king(cb, from_row, from_col, to_row, to_col);
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default:
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DEBUG("can_move: piece not implemented\n");
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return false;
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}
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}
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void find_other_king(struct chessboard *cb, enum player p,
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int* k_row, int* k_col) {
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for (*k_row = 0; *k_row < 8; (*k_row)++) {
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for (*k_col = 0; *k_col < 8; (*k_col)++) {
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if ((p == BLACK && cb->position[*k_row][*k_col] == WHITE_KING) ||
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(p == WHITE && cb->position[*k_row][*k_col] == BLACK_KING))
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{
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DEBUG("find_other_king: %s king in position row %d col %d\n",
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p == WHITE ? "black" : "white", *k_row, *k_col);
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return;
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}
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}
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}
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DEBUG("find_king: king not found");
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}
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bool player_checks(struct chessboard *cb, enum player p) {
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int k_row, k_col;
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find_other_king(cb, p, &k_row, &k_col);
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int i, j;
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for (i = 0; i < 8; i++) {
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for (j = 0; j < 8; j++) {
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if (!is_empty(cb, i, j) && player(cb, i, j) == p) {
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DEBUG("player_checks: checking row %d col %d to attack king\n",
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i, j);
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if (can_move(cb, p, i, j, k_row, k_col)) {
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DEBUG("player_checks: row %d col %d can attack %s king\n",
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i, j, p == WHITE ? "black" : "white");
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return true;
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}
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}
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}
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}
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return false;
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}
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enum mstatus move(
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struct chessboard * cb, enum player p,
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const char * from, const char * to)
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{
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const char * from, const char * to) {
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// if you are giving us garbage, we behave like Rome's municipal services
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if (strlen(from) != 2 || strlen(to) != 2 || from[0] < 'a' || from[0] > 'h'
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|| to[0] < 'a' || to[0] > 'h' || from[1] < '1' || from[1] > '8'
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|| to[1] < '1' || to[1] > '8') {
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if (strlen(from) != 2 || from[0] < 'a' || from[0] > 'h' || from[1] < '1'
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|| from[1] > '8') {
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DEBUG("move: 'from' input '%s' is invalid\n", from);
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return INVALID;
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}
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if (to[0] < 'a' || to[0] > 'h' || to[1] < '1' || to[1] > '8'
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|| strlen(to) != 2) {
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DEBUG("move: 'to' input '%s' is invalid\n", to);
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return INVALID;
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}
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int from_row = from[0] - 'a', to_row = to[0] - 'a';
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int from_col = from[1] - '1', to_col = to[0] - '1';
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int from_col = from[0] - 'a', to_col = to[0] - 'a';
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int from_row = from[1] - '1', to_row = to[1] - '1';
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// if you are moving thin air, EH VOLEVIH
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if (is_empty(cb, from_row, from_col)) {
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DEBUG("move: from is empty\n");
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return INVALID;
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}
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// if you are moving someone else's pieces, "thou shall not steal"
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if (player(cb, from_row, from_col) != p) {
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DEBUG("move: moving piece of opponent\n");
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return INVALID;
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}
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@ -203,32 +321,67 @@ enum mstatus move(
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if (cb->position[to_row][to_col] != EMPTY &&
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cb->position[from_row][from_col] / 7 ==
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cb->position[to_row][to_col] / 7) {
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DEBUG("move: capturing piece from moving player\n");
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return INVALID;
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}
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// if you try to move on the same spot, don't do it you buffoon
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if (from_row == to_row && from_col == to_col) {
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DEBUG("move: moving to same position\n");
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return INVALID;
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}
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// try to understand which piece we are moving
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switch (cb->position[from_row][from_col]) {
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case WHITE_PAWN:
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case BLACK_PAWN:
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return move_pawn(cb, p, from_row, from_col, to_row, to_col);
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case WHITE_ROOK:
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case BLACK_ROOK:
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return move_rook(cb, p, from_row, from_col, to_row, to_col);
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case WHITE_BISHOP:
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case BLACK_BISHOP:
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return move_bishop(cb, p, from_row, from_col, to_row, to_col);
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case WHITE_QUEEN:
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case BLACK_QUEEN:
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return move_queen(cb, p, from_row, from_col, to_row, to_col);
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case WHITE_KNIGHT:
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case BLACK_KNIGHT:
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return move_knight(cb, p, from_row, from_col, to_row, to_col);
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default:
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bool can = can_move(cb, p, from_row, from_col, to_row, to_col);
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if (!can) {
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return INVALID;
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} else {
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cb_move(cb, from_row, from_col, to_row, to_col);
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if (player_checks(cb, p)) {
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// TODO: check checkmate
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return CHECK;
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} else {
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return VALID;
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}
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}
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}
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int main() {
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struct chessboard cb;
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init_chessboard(&cb);
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enum player p = WHITE;
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char from[5], to[5];
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from[0] = '\0';
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while(1) {
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print_chessboard(&cb);
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printf("%s moves.\n", p == WHITE ? "White" : "Black");
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printf("From: ");
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fgets(from, 5, stdin);
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// remove trailing \n: https://stackoverflow.com/q/2693776
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strtok(from, "\n");
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if (strcmp(from, "exit") == 0) {
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printf("Exiting...\n");
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return 0;
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}
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printf("To: ");
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fgets(to, 5, stdin);
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strtok(to, "\n");
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enum mstatus s = move(&cb, p, from, to);
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switch (s) {
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||||
case INVALID:
|
||||
printf("Invalid move.\n");
|
||||
break;
|
||||
case VALID:
|
||||
printf("No check/checkmate.\n");
|
||||
break;
|
||||
case CHECK:
|
||||
printf("Check.\n");
|
||||
break;
|
||||
case CHECK_MATE:
|
||||
printf("Checkmate, %s wins.\n", p == WHITE ? "white" : "black");
|
||||
}
|
||||
if (s != INVALID) {
|
||||
p = !p; // switch player: this works since WHITE = 0 and BLACK = 1
|
||||
}
|
||||
}
|
||||
}
|
||||
|
|
|
|||
Reference in a new issue