代码：

#include <bits/stdc++.h>
using namespace std;
vector<int> a,b,c;
string s1,s2;
int main(){
    cin >> s1 >> s2;
    int len1 = s1.size(),len2 = s2.size();
    for(int i = 0;i < len1;i++)a.push_back(s1[len1 - 1 - i] - '0');
    for(int i = 0;i < len2;i++)b.push_back(s2[len2 - 1 - i] - '0');
    int jin = 0;
    for(int i = 0;i < max(len1,len2);i++){
        c.push_back(a[i] + b[i] + jin);
        jin = c[i] / 10;
        c[i] %= 10;
    }
    if(jin == 1)c.push_back(1);
    for(int i = c.size() - 1;i >= 0;i --)cout << c[i];
    return 0;
}

#5 WA