c - C 语言中是/否提示？

Question

我使用“是/否”用户提示来确定用户是否想要执行该程序或退出该程序...当您键入 y 或 Y 时，它将再次执行该程序。但是，任何其他字符(不仅仅是 n 或 N)都将终止该程序。我想知道如何解决这个问题？

int main() {
    unsigned num;
    char response;

    do {
        printf("Please enter a positive integer greater than 1 and less than 2000: ");
        scanf("%d", & num);
        if(num > 1 && num < 2000) {
            printf("All the prime factors of %d are given below: \n", num);
            printPrimeFactors(num);
            printf("\n\nThe distinct prime factors of %d are given below: \n", num);
            printDistinctPrimeFactors(num);
        } else {
            printf("Sorry that number does not fall within the given range.\n");
        }
        printf("\n\nDo you want to try another number? Say Y(es) or N(o): ");
        getchar();
        response = getchar();
    }
    while (response == 'Y' || response == 'y'); // if response is Y or y then program runs again
        printf("Thank you for using my program. Good Bye!\n\n"); //if not Y or y, program terminates
    return 0;
}

Answer 1

我希望您期望以下逻辑仅得到 y、Y、n 或 N 作为使用的输入来做出决定。

do
{
    ...

    r = getchar();
    if (r == '\n') r = getchar();
    while(r != 'n' && r != 'N' && r != 'y` && r != `Y`)
    {
        printf("\invalid input, enter the choice(y/Y/n/N) again : ");
        r = getchar();
        if (r == '\n') r = getchar();
    }
}while(r == 'Y' || r == 'y');