C语言编程题实现一个简易的井字棋游戏

1、使用二维数组和循环

最常见的实现方法，使用一个二维数组表示棋盘，使用循环和条件判断来控制游戏逻辑。

#include <stdio.h>

#define SIZE 3

void displayBoard(char board[SIZE][SIZE]) {
    printf("\n");
    for (int i = 0; i < SIZE; i++) {
        for (int j = 0; j < SIZE; j++) {
            printf(" %c ", board[i][j]);
            if (j < SIZE - 1) printf("|");
        }
        if (i < SIZE - 1) printf("\n---|---|---\n");
    }
    printf("\n");
}

int checkWin(char board[SIZE][SIZE]) {
    for (int i = 0; i < SIZE; i++) {
        // 行检查
        if (board[i][0] == board[i][1] && board[i][1] == board[i][2]) {
            return (board[i][0] == 'X') ? 1 : (board[i][0] == 'O') ? 2 : 0;
        }
        // 列检查
        if (board[0][i] == board[1][i] && board[1][i] == board[2][i]) {
            return (board[0][i] == 'X') ? 1 : (board[0][i] == 'O') ? 2 : 0;
        }
    }
    // 对角线检查
    if (board[0][0] == board[1][1] && board[1][1] == board[2][2]) {
        return (board[0][0] == 'X') ? 1 : (board[0][0] == 'O') ? 2 : 0;
    }
    if (board[0][2] == board[1][1] && board[1][1] == board[2][0]) {
        return (board[0][2] == 'X') ? 1 : (board[0][2] == 'O') ? 2 : 0;
    }
    return 0;
}

int main() {
    char board[SIZE][SIZE] = {{'1', '2', '3'}, {'4', '5', '6'}, {'7', '8', '9'}};
    int player = 1, choice, row, col, result = 0;
    char mark;

    while (result == 0) {
        displayBoard(board);
        player = (player % 2) ? 1 : 2;
        mark = (player == 1) ? 'X' : 'O';

        printf("Player %d, enter the number where you want to place %c: ", player, mark);
        scanf("%d", &choice);

        row = (choice - 1) / SIZE;
        col = (choice - 1) % SIZE;

        if (choice >= 1 && choice <= 9 && board[row][col] != 'X' && board[row][col] != 'O') {
            board[row][col] = mark;
        } else {
            printf("Invalid move, try again.\n");
            player--;
        }

        result = checkWin(board);
        player++;
    }

    displayBoard(board);
    if (result == 1) {
        printf("Player 1 wins!\n");
    } else if (result == 2) {
        printf("Player 2 wins!\n");
    } else {
        printf("It's a draw!\n");
    }

    return 0;
}

2、使用递归

使用递归来处理游戏循环，通过递归函数进行多次调用直到游戏结束。

#include <stdio.h>

#define SIZE 3

void displayBoard(char board[SIZE][SIZE]) {
    printf("\n");
    for (int i = 0; i < SIZE; i++) {
        for (int j = 0; j < SIZE; j++) {
            printf(" %c ", board[i][j]);
            if (j < SIZE - 1) printf("|");
        }
        if (i < SIZE - 1) printf("\n---|---|---\n");
    }
    printf("\n");
}

int checkWin(char board[SIZE][SIZE]) {
    for (int i = 0; i < SIZE; i++) {
        if (board[i][0] == board[i][1] && board[i][1] == board[i][2]) {
            return (board[i][0] == 'X') ? 1 : (board[i][0] == 'O') ? 2 : 0;
        }
        if (board[0][i] == board[1][i] && board[1][i] == board[2][i]) {
            return (board[0][i] == 'X') ? 1 : (board[0][i] == 'O') ? 2 : 0;
        }
    }
    if (board[0][0] == board[1][1] && board[1][1] == board[2][2]) {
        return (board[0][0] == 'X') ? 1 : (board[0][0] == 'O') ? 2 : 0;
    }
    if (board[0][2] == board[1][1] && board[1][1] == board[2][0]) {
        return (board[0][2] == 'X') ? 1 : (board[0][2] == 'O') ? 2 : 0;
    }
    return 0;
}

void playGame(char board[SIZE][SIZE], int player) {
    int choice, row, col, result = checkWin(board);
    char mark = (player == 1) ? 'X' : 'O';

    if (result != 0) {
        displayBoard(board);
        if (result == 1) {
            printf("Player 1 wins!\n");
        } else if (result == 2) {
            printf("Player 2 wins!\n");
        } else {
            printf("It's a draw!\n");
        }
        return;
    }

    displayBoard(board);
    printf("Player %d, enter the number where you want to place %c: ", player, mark);
    scanf("%d", &choice);

    row = (choice - 1) / SIZE;
    col = (choice - 1) % SIZE;

    if (choice >= 1 && choice <= 9 && board[row][col] != 'X' && board[row][col] != 'O') {
        board[row][col] = mark;
    } else {
        printf("Invalid move, try again.\n");
        playGame(board, player);
        return;
    }

    playGame(board, (player % 2) + 1);
}

int main() {
    char board[SIZE][SIZE] = {{'1', '2', '3'}, {'4', '5', '6'}, {'7', '8', '9'}};

    printf("Welcome to Tic Tac Toe!\n");
    playGame(board, 1);

    return 0;
}

3、使用位运算和状态存储

通过位运算来跟踪玩家的获胜条件，利用较少的空间处理状态。

#include <stdio.h>

#define SIZE 3
#define FULL_BOARD (1 << (SIZE * SIZE)) - 1

int board = 0, player1 = 0, player2 = 0;

void displayBoard(int p1, int p2) {
    printf("\n");
    for (int i = 0; i < SIZE * SIZE; i++) {
        if (p1 & (1 << i)) {
            printf(" X ");
        } else if (p2 & (1 << i)) {
            printf(" O ");
        } else {
            printf(" %d ", i + 1);
        }
        if ((i + 1) % SIZE == 0 && i != SIZE * SIZE - 1) {
            printf("\n---|---|---\n");
        } else if ((i + 1) % SIZE != 0) {
            printf("|");
        }
    }
    printf("\n");
}

int checkWin(int player) {
    int wins[] = {
        0b111000000, // Row 1
        0b000111000, // Row 2
        0b000000111, // Row 3
        0b100100100, // Col 1
        0b010010010, // Col 2
        0b001001001, // Col 3
        0b100010001, // Diagonal 1
        0b001010100  // Diagonal 2
    };

    for (int i = 0; i < 8; i++) {
        if ((player & wins[i]) == wins[i]) {
            return 1;
        }
    }
    return 0;
}

int main() {
    int currentPlayer = 1, choice;
    printf("Welcome to Tic Tac Toe!\n");

    while (board != FULL_BOARD) {
        displayBoard(player1, player2);
        printf("Player %d, enter your move (1-9): ", currentPlayer);
        scanf("%d", &choice);

        if (choice < 1 || choice > 9 || (board & (1 << (choice - 1)))) {
            printf("Invalid move, try again.\n");
            continue;
        }

        board |= (1 << (choice - 1));

        if (currentPlayer == 1) {
            player1 |= (1 << (choice - 1));
            if (checkWin(player1)) {
                displayBoard(player1, player2);
                printf("Player 1 wins!\n");
                return 0;
            }
        } else {
            player2 |= (1 << (choice - 1));
            if (checkWin(player2)) {
                displayBoard(player1, player2);
                printf("Player 2 wins!\n");
                return 0;
            }
        }

        currentPlayer = 3 - currentPlayer; // Alternate between player 1 and 2
    }

    printf("It's a draw!\n");
    return 0;
}