我看看是谁不用string！啊！

#include<bits/stdc++.h>
using namespace std;
int main(){
    string a,b,c;
    int jw = 0;
    cin >> a >> b;
    reverse(a.begin(),a.end());
    reverse(b.begin(),b.end());
    for(int i = 0;i < max(a.size(),b.size());i++){
        int z1 = 0,z2 = 0;
        if(a.size() > i) z1 = a[i] - '0';
        if(b.size() > i) z2 = b[i] - '0';
        int s = z1 + z2 + jw;
        if(s >= 10){
            s = s % 10;
            jw = 1;
        } else {
            jw = 0;
        }
        c += s + '0';
    }
    if(jw == 1) c += '1';
    reverse(c.begin(),c.end());
    cout << c;
    return 0;
}