有人可以解决这个代码块吗？

Question

帮我解决这个问题，因为我真的不知道

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

int main() {
    char ans;

    printf("1. The patients felt _____ after taking the medicine.\n");
    printf("\t a. best\n\t b. better\n\t c. good\n\n");
    scanf("%c", &ans);

    if (ans == 'b') {
        printf("2. I ______ my essay by the time the bell rings.\n");
        printf("\t a. have done\n\t b. shall do\n\t c. shall have done\n\n");
        scanf("%c", &ans);
    } else {
        printf("YOU FAILED!");
    };
    return 0;
}

如果您回答了第一个问题，您将继续下一步并回答第二个问题，但问题是即使有 scanf，我也无法输入答案。

Answer 1

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

int main() {
    char ans;

    printf("1. The patients felt _____ after taking the medicine.\n");
    printf("\t a. best\n\t b. better\n\t c. good\n\n");
    scanf("%c", &ans);

    if (ans == 'b') {
        printf("2. I ______ my essay by the time the bell rings.\n");
        printf("\t a. have done\n\t b. shall do\n\t c. shall have done\n\n");
        scanf(" %c", &ans);
    } else {
        printf("YOU FAILED!");
    };

    return 0;
}

区别在于:

scanf(" %c",&ans);
       ^ this space this will read whitespace characters (which newline also is)
         until it finds a non space character.

scanf 没有消耗第一次 scanf 调用时留在缓冲区中的 \n 字符。

我尝试了这个，它有效!