你是一个清华大学计算机的学生，请做一份c语言程序五子棋小游戏

好的，以下是一个简单的C语言五子棋小游戏程序：

#include <stdio.h>
#include <stdlib.h>

#define SIZE 15

char board[SIZE][SIZE];

void init_board() {
    int i, j;
    for (i = 0; i < SIZE; i++) {
        for (j = 0; j < SIZE; j++) {
            board[i][j] = '.';
        }
    }
}

void print_board() {
    int i, j;
    printf("\n");
    for (i = 0; i < SIZE; i++) {
        printf("%2d ", i);
        for (j = 0; j < SIZE; j++) {
            printf("%c ", board[i][j]);
        }
        printf("\n");
    }
    printf("      ");
    for (i = 0; i < SIZE; i++) {
        printf("%d ", i);
    }
    printf("\n");
}

int check_win(int x, int y) {
    char c = board[x][y];
    int i, j, cnt;
    // check row
    cnt = 0;
    for (j = 0; j < SIZE; j++) {
        if (board[x][j] == c) {
            cnt++;
            if (cnt == 5) return 1;
        } else {
            cnt = 0;
        }
    }
    // check column
    cnt = 0;
    for (i = 0; i < SIZE; i++) {
        if (board[i][y] == c) {
            cnt++;
            if (cnt == 5) return 1;
        } else {
            cnt = 0;
        }
    }
    // check diagonal
    cnt = 0;
    for (i = x, j = y; i >= 0 && j >= 0; i--, j--) {
        if (board[i][j] == c) {
            cnt++;
            if (cnt == 5) return 1;
        } else {
            break;
        }
    }
    for (i = x+1, j = y+1; i < SIZE && j < SIZE; i++, j++) {
        if (board[i][j] == c) {
            cnt++;
            if (cnt == 5) return 1;
        } else {
            break;
        }
    }
    // check anti-diagonal
    cnt = 0;
    for (i = x, j = y; i >= 0 && j < SIZE; i--, j++) {
        if (board[i][j] == c) {
            cnt++;
            if (cnt == 5) return 1;
        } else {
            break;
        }
    }
    for (i = x+1, j = y-1; i < SIZE && j >= 0; i++, j--) {
        if (board[i][j] == c) {
            cnt++;
            if (cnt == 5) return 1;
        } else {
            break;
        }
    }
    return 0;
}

int main() {
    int x, y, turn = 0;
    init_board();
    while (1) {
        print_board();
        if (turn % 2 == 0) {
            printf("Player 1's turn (X)\n");
        } else {
            printf("Player 2's turn (O)\n");
        }
        printf("Enter the position (x, y): ");
        scanf("%d%d", &x, &y);
        if (x < 0 || x >= SIZE || y < 0 || y >= SIZE) {
            printf("Invalid position!\n");
            continue;
        }
        if (board[x][y] != '.') {
            printf("This position is already occupied!\n");
            continue;
        }
        board[x][y] = (turn % 2 == 0 ? 'X' : 'O');
        if (check_win(x, y)) {
            print_board();
            if (turn % 2 == 0) {
                printf("Player 1 (X) wins!\n");
            } else {
                printf("Player 2 (O) wins!\n");
            }
            break;
        }
        turn++;
    }
    return 0;
}

这个程序实现了一个基本的五子棋游戏，先让用户输入坐标，然后判断是否合法，如果合法则在棋盘上落子，并且判断是否胜利。如果胜利则输出获胜者，并结束游戏。