题解 | a+b

#include <iostream>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <string>
using namespace std;

string Add(string s1, string s2) {//高精度加法模板
    int l1= s1.size(),l2 = s2.size();
    if (l1 < l2)swap(s1, s2);
    reverse(s1.begin(), s1.end());
    reverse(s2.begin(), s2.end());
    int car = 0;
    string s = "";
    for (int i = 0; i < s2.size(); i++) {
        int num = (s1[i] - '0') + (s2[i] - '0') + car;
        char c = num % 10 + '0';
        s = s + c;
        car = num / 10;
    }
    for (int i = s2.size(); i < s1.size(); i++) {
        int num = (s1[i] - '0')  + car;
        char c = num % 10 + '0';
        s = s + c;
        car = num / 10;
    }
    reverse(s.begin(),s.end());
    while(s[0]==0)s.erase(0,1);
    return s;
}

int main() {
    string s1, s2;
    while (cin >> s1 >> s2) {
        
        string ans = Add(s1,s2);
  //      cout<<ans.size()<<endl;
        cout<<ans<<endl;
    }
}
// 64 位输出请用 printf("%lld")