1001 A+B Format (20 point(s))

1001 A+B Format (20 point(s))

The situation is divided into 0 and non-0 cases. The result is 0. The case is directly output, and the non-0 case: if it is less than 0, the negative sign is output first, and then dfs uses its backtracking to output each bit.

#include <stdio.h>
#include <iostream>
using namespace std;

void dfs(int c,int cnt){
    
    
    if(c == 0) return;
    dfs(c/10,cnt+1);
    if(cnt%3 == 0 && c>=10) putchar(',');
    printf("%d",c%10);
}
int main(){
    
    
    int a,b;cin>>a>>b;
    if(a + b == 0) puts("0");
    else{
    
    
        if(a + b < 0) putchar('-');
        dfs(abs(a+b),1);
    }


    return 0;
}