题解 | #添加逗号#

这太暴力了

#include <stdio.h>
#include<string.h>
int main() {
    char a[10];
    scanf("%s", a);
    int t = 0;
    if (strlen(a) % 3 == 0 && strlen(a) != 1 && strlen(a) != 2) {
        for (int i = 0; i < strlen(a); i++) {
            printf("%c", a[i]);
            t = t + 1;
            if (t == 3 && i != strlen(a) - 1) {
                printf(",");
                t = 0;
            }
        }

    } else if (strlen(a) % 3 == 1 && strlen(a) != 1 && strlen(a) != 2) {
        printf("%c,", a[0]);
        for (int i = 1; i < strlen(a); i++) {
            printf("%c", a[i]);
            t = t + 1;
            if (t == 3 && i != strlen(a) - 1) {
                printf(",");
                t = 0;
            }
        }
    } else if (strlen(a) % 3 == 2 && strlen(a) != 1 && strlen(a) != 2) {
        printf("%c%c,", a[0], a[1]);
        for (int i = 2; i < strlen(a); i++) {
            printf("%c", a[i]);
            t = t + 1;
            if (t == 3 && i != strlen(a) - 1) {
                printf(",");
                t = 0;
            }
        }
    } else {
        for (int i = 0; i < strlen(a); i++) {
            printf("%c", a[i]);
        }
    }
    return 0;
}