题解

有点复杂...

#include<bits/stdc++.h>
using namespace std;
#define int long long
void FIX(string& s,int length) {
	reverse(s.begin(),s.end());
	while (s.length()!=length) {
		s.push_back('0');
	}
	for (int i=0;i<s.size();i++) {
		s[i]-='0';
	}
}
void RESULT(string& s) {
	while (s.size()>1&&s.back()=='0')s.pop_back();
	reverse(s.begin(),s.end());
}
signed main() {
	string a,b;
	cin>>a>>b;
	int length=max(a.size(), b.size());
	string c(length+1,0);
	FIX(a,length);
	FIX(b,length); 
	for(int i=0;i<a.size();i++){
        c[i]+=a[i]+b[i];
        if(c[i]>9){
            c[i+1]+=1;
            c[i]%=10;
        }
        c[i]+='0';
        if(i==a.size()-1){
            c[i+1]+='0';
        }
    }
	RESULT(c);cout<<c<<endl;
	return 0;
}