Greater Integers

input/code.cpp: In function 'void usaco(std::__cxx11::string)':
input/code.cpp:12:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen((s+".in").c_str(), "r", stdin);
   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
input/code.cpp:13:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   freopen((s+".out").c_str(), "w", stdout);
   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#include <bits/stdc++.h>
using namespace std;
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<ll, ll> pii;
typedef vector<ll> vi;
typedef vector<pii> vpi;

void usaco(string s){
  freopen((s+".in").c_str(), "r", stdin);
  freopen((s+".out").c_str(), "w", stdout);
}

int main() {
	cin.tie(0)->sync_with_stdio(0);
	cin.exceptions(cin.failbit);
#ifdef LOCAL_DEFINE
	freopen("input.txt", "r", stdin);
#endif
  int t;
  cin >> t;
  while(t--){
    int n, old;
    cin >> n;
    old = n;
    int dig = 0, last = 0;
    while(n){
      last = n%10;
      n /= 10;
      dig++;
    }
    int no=0;
    for(int i = 1; i <= dig; i++){
      no = (no*10) + last;
    }
    if(no <= old){
      last += 1;
      last %= 10;
      if(last == 0){ last = 1; dig++; }
      no = 0;
      for(int i = 1; i <= dig; i++){
      	no = (no*10) + last;
    	}
    }
    cout << no << '\n';
  }
}

Test 1

Group: 1, 2

Verdict: ACCEPTED

Test 2

Group: 2

Verdict: RUNTIME ERROR

terminate called after throwing an instance of 'std::__ios_failure'
  what():  basic_ios::...