题解 | 数字反转

#include <iostream>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <iterator>
#include <string>
using namespace std;
string Add(string s1,string s2)
{
    int l1 = s1.size(),l2 = s2.size();
    if(l1<l2)swap(s1,s2);
    reverse(s1.begin(),s1.end());
    reverse(s2.begin(),s2.end());
    string s = "";
    int car = 0;
    for(int i=0;i<s2.size();i++)
    {
        int num = (s1[i]-'0')+(s2[i]-'0') + car;
        car = num/10;
        char c = '0' + num%10;
        s = s+c;
    }
    for(int i = s2.size();i<s1.size();i++)
    {
        int num = (s1[i]-'0') + car;
        car = num/10;
        char c = '0' + num%10;
        s = s+c;
    }
    if(car!=0)s = s+'1';
    reverse(s.begin(),s.end());
    while(s[0]=='0')s.erase(0,1);
    return s;
}
int main() {
    string a,b;
    while(cin>>a>>b)
    {
        string ans1 = Add(a,b);
        reverse(ans1.begin(),ans1.end());
        reverse(a.begin(),a.end());
        reverse(b.begin(),b.end());
        string ans2 = Add(a,b);
        if(ans1==ans2)
        {
            reverse(ans1.begin(),ans1.end());
            cout<<ans1<<endl;
        }
        else cout<<"NO"<<endl;
//        cout<<ans1<<endl;
    }
}
// 64 位输出请用 printf("%lld")