Vuodet

#include <iostream>
#include <vector>
using namespace std;
auto leet = [](int x) {
  auto str = to_string(x * 1337);
  auto x_str = to_string(x);
  int j = 0;
  for (char c : str) {
    if (j < 4 && c == x_str[j]) ++j;
  }
  return j == 4;
};
int main() {
  int a, b;
  cin >> a >> b;
  vector<int> r;
  for (int i = a; i <= b; i++) {
    if (leet(i)) r.push_back(i);
  }
  cout << size(r) << endl;
  for (auto u : r) cout << u << '\n';
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED