Greater Integers

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define pb push_back
#define ppb pop_back
#define x first
#define y second
#define int long long
#define mp make_pair

using namespace std;

const int inf = 1e18, sz = 105;

signed main (){
//    cin.tie(0);
//    ios_base::sync_with_stdio(0);
    int t;
    cin >> t;
    set <int> s;
    for (int i = 1; i <= 9; ++i){
        string num;
        for (int j = 1; j <= 18; ++j){
            num += char(i + '0');
            s.insert(stoll(num));
        }
    }
    while (t--){
        int n;
        cin >> n;
        if (n == 1e18 || n == 1e18-1){
            for (int j = 1; j <= 19; ++j){
                cout << 1;
            }
            cout << '\n';
        }
        else cout << *s.upper_bound(n) << '\n';
    }
    return 0;
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: ACCEPTED