ModAdd

input/code.cpp: In function 'int main()':
input/code.cpp:16:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (i >= b.size()) {
             ~~^~~~~~~~~~~
input/code.cpp:18:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         } else if (i >= a.size()) {
                    ~~^~~~~~~~~~~

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

string a;
string b;
int res[1010101];

int main() {
    cin >> a >> b;
    reverse(a.begin(),a.end());
    reverse(b.begin(),b.end());
    int len = max(a.size(), b.size());

    for (int i = 0; i < len; i++) {
        if (i >= b.size()) {
            res[i] = a[i]-'0';
        } else if (i >= a.size()) {
            res[i] = b[i]-'0';
         } else {
            int x = a[i]-'0'+b[i]-'0';
            res[i] = x%10;
        }
    }
    bool print = false;
    for (int i = len-1; i >= 0; i--) {
        if (res[i]) print = true;
        if (print) cout << res[i];
    }
    if (!print) cout << 0;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED