题解 | 反向输出一个四位数

#include <stdio.h>

int main() {
    int num = 0;
    int product_sum = 1;
    int a = 0;
    int sum = 0;
    int count = 0;
    int sum_count = 0;
    scanf("%d", &num);
    while (num != 0) {
        a = num % 10;
        sum = sum * 10 + a;
        num /= 10;
        count++;//统计几位数字
    }
    int b = sum;
    while (b != 0) {
        sum_count++;
        b /= 10;
    }
    if (sum_count != count) {
        for (int i = 1; i <= count - sum_count; i++) {
            printf("0");
        }
    }
    printf("%d", sum);
    return 0;
}

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