题解

#include <bits/stdc++.h>
using namespace std;
void Readsum(string a,string b){
    string c="";
    int k = min(a.size(),b.size());
    int l = max(a.size(),b.size())-k;
    int flag = 0;
    for (int i=0;i<k;i++){
        char d = a[k-1-i]-'0'+b[k-1-i]-'0'+flag;
        if (d > '9'){
            d -= 10;
            flag = 1;
        }char e = d+48;
        c = e+c;
        if (d <= '9'){
            flag = 0;
        }
    }printf("%s",c.c_str());
}
int main(){
    string a,b;
    cin >> a >> b;
    string A=a,B=b;
    if (A.size() > B.size()){
        for (int i=0;B.size() < A.size();i++){
            B = "0"+B;
        }
    }if (A.size() < B.size()){
        for (int i=0;B.size() > A.size();i++){
            A = "0"+A;
        }
    }
    Readsum(A,B);
    return 0;
}