C语言石头剪刀布程序异常：输入选择后为何重复请求输入？

核心问题 #

程序陷入无限请求输入的循环，根源是整数与字符的错误比较：

• computer_choice是整数类型，rand() % 3生成的是0、1、2这三个整数
• 但你在条件判断里把它和字符'0'、'1'、'2'比较（比如computer_choice == '0'），整数0和字符'0'的ASCII值（48）不相等，导致所有胜负判断的条件都无法触发
• 最终player_score和computer_score永远达不到3，do-while循环的终止条件player_score < 3 && computer_score < 3一直为真，程序持续重复请求输入

修复步骤 #

1. 修正数值比较逻辑：把所有条件中的'0'、'1'、'2'改成整数0、1、2，比如将computer_choice == '0'改为computer_choice == 0，所有类似判断都要修改。
2. 添加非法输入处理（推荐）：当前程序未处理非r/p/s的输入，可在所有条件后加else分支提示输入错误，避免无效输入导致的循环。
3. 修复分数显示逻辑：原代码仅在双方分数都不为0时显示分数，改为只要有一方有分数就显示，更符合游戏逻辑。
4. 重置分数（隐藏问题修复）：新增游戏重启时的分数重置逻辑，避免下一局延续上一局的分数。

修复后的完整代码 #

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

int main() {
    int player_score = 0, computer_score = 0;
    char player_choice2;

    printf("\nWELCOME TO ROCK PAPER SCISSORS !\n\nFirst to get three points wins\n\n");

    srand(time(NULL));

    for (;;) {
        do {
            char player_choice;
            int computer_choice = rand() % 3;

            // 修复分数显示条件
            if (player_score > 0 || computer_score > 0) {
                printf("Your score: %d\nComputer's score: %d\n\n", player_score, computer_score);
            }

            printf("Choose between r for rock, p for paper and s for scissors\n\n");
            scanf(" %c", &player_choice);

            // 修正整数与字符的比较
            if (player_choice == 'r' && computer_choice == 0) {
                printf("Rock! It's a tie.\n\n");
            } else if (player_choice == 'p' && computer_choice == 0) {
                printf("Rock!\n\n");
                player_score += 1;
            } else if (player_choice == 's' && computer_choice == 0) {
                printf("Rock!\n\n");
                computer_score += 1;
            } else if (player_choice == 'r' && computer_choice == 1) {
                printf("Paper!\n\n");
                computer_score += 1;
            } else if (player_choice == 'p' && computer_choice == 1) {
                printf("Paper! It's a tie.\n\n");
            } else if (player_choice == 's' && computer_choice == 1) {
                printf("Paper!\n\n");
                player_score += 1;
            } else if (player_choice == 'r' && computer_choice == 2) {
                printf("Scissors!\n\n");
                player_score += 1;
            } else if (player_choice == 'p' && computer_choice == 2) {
                printf("Scissors!\n\n");
                computer_score += 1;
            } else if (player_choice == 's' && computer_choice == 2) {
                printf("Scissors! It's a tie.\n\n");
            } else {
                // 添加非法输入提示
                printf("Invalid input! Please enter r, p or s.\n\n");
            }

        } while (player_score < 3 && computer_score < 3);

        if (player_score == 3) {
            printf("Congratulations, you won !\n\n");
        } else {
            printf("Sorry, you lost !\n\n");
        }

        printf("Do you wish to play again ? Enter Y for yes or N for no\n");
        scanf(" %c", &player_choice2);
        if (player_choice2 == 'N') {
            break;
        }
        // 重置分数，准备下一局
        player_score = 0;
        computer_score = 0;
    }
    return 0;
}

内容的提问来源于stack exchange，提问作者Clément