Problem p02571 (C++) — buggy submission, verdict: Runtime Error

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\\'' << x << '\\''; }
void __print(const char *x) { cerr << '\\"' << x << '\\"'; }
void __print(const string &x) { cerr << '\\"' << x << '\\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template <typename T, typename V> void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T> void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x)
    cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\\n"; }
template <typename T, typename... V> void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v))
    cerr << ", ";
  _print(v...);
}
#ifndef ONLINE_JUDGE
#define debug(x...)                                                            \\
  cerr << "[" << #x << "] = [";                                                \\
  _print(x)
#else
#define debug(x...)
#endif
const long long INF = 1e18;
int md = 1e9 + 7;

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  string s, t;
  cin >> s >> t;
  int ans = INT_MAX;
  for (int i = 0; i <= s.length() - t.length(); i++) {

    int j = 0;
    int cnt = 0;
    for (int it = i; j < t.length(); it++, j++) {
      if (s[it] != t[j]) {
        cnt++;
      }
    }
    // debug(i,cnt);
    ans = min(ans, cnt);
  }
  cout << ans;
}

// https://www.youtube.com/watch?v=ZQqccia8bVo

Error: WA

Fixed submission:

#include <bits/stdc++.h>

using namespace std;
typedef long long ll;
void __print(int x) { cerr << x; }
void __print(long x) { cerr << x; }
void __print(long long x) { cerr << x; }
void __print(unsigned x) { cerr << x; }
void __print(unsigned long x) { cerr << x; }
void __print(unsigned long long x) { cerr << x; }
void __print(float x) { cerr << x; }
void __print(double x) { cerr << x; }
void __print(long double x) { cerr << x; }
void __print(char x) { cerr << '\\'' << x << '\\''; }
void __print(const char *x) { cerr << '\\"' << x << '\\"'; }
void __print(const string &x) { cerr << '\\"' << x << '\\"'; }
void __print(bool x) { cerr << (x ? "true" : "false"); }

template <typename T, typename V> void __print(const pair<T, V> &x) {
  cerr << '{';
  __print(x.first);
  cerr << ',';
  __print(x.second);
  cerr << '}';
}
template <typename T> void __print(const T &x) {
  int f = 0;
  cerr << '{';
  for (auto &i : x)
    cerr << (f++ ? "," : ""), __print(i);
  cerr << "}";
}
void _print() { cerr << "]\\n"; }
template <typename T, typename... V> void _print(T t, V... v) {
  __print(t);
  if (sizeof...(v))
    cerr << ", ";
  _print(v...);
}
#ifndef ONLINE_JUDGE
#define debug(x...)                                                            \\
  cerr << "[" << #x << "] = [";                                                \\
  _print(x)
#else
#define debug(x...)
#endif
const long long INF = 1e18;
int md = 1e9 + 7;

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  string s, t;
  cin >> s >> t;
  assert(t.length() < s.length());
  int ans = INT_MAX;
  for (int i = 0; i <= s.length() - t.length(); i++) {

    int j = 0;
    int cnt = 0;
    for (int it = i; j < t.length(); it++, j++) {
      if (s[it] != t[j]) {
        cnt++;
      }
    }
    // debug(i,cnt);
    ans = min(ans, cnt);
  }
  cout << ans;
}

// https://www.youtube.com/watch?v=ZQqccia8bVo