PAT刷题

1001. A+B Format (20)

[code]#include <cmath>
#include <cstdio>
#include <iostream>

using namespace std;

char str[100];

int main(){
    // freopen("I-in.txt", "r", stdin);
    int a, b;
    scanf("%d%d", &a, &b);
    int c = a + b;
    int flag = 0;
    if(c < 0) flag = 1;
    int pos = 1;
    int tmp = abs(c);
    while(tmp){
        if(pos%4 == 0)str[pos++] = ',';
        str[pos++] = '0' + tmp % 10;
        tmp /= 10;
    }
    if(flag) printf("-");
    for(int i = pos - 1; i >= 1; i--)
        printf("%c", str[i]);
    if(!c) printf("0");
    printf("\n");
    return 0;
}