Vuodet

input/code.cpp: In function 'int main()':
input/code.cpp:21:37: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   21 |                         if (matches < xstr.size() && c == xstr[matches]) ++matches;
      |                             ~~~~~~~~^~~~~~~~~~~~~
input/code.cpp:23:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |                 if (matches == xstr.size()) res.push_back(x);
      |                     ~~~~~~~~^~~~~~~~~~~~~~

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

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);

	int a, b;
	cin >> a >> b;

	vector<int> res;
	for (int x = a; x <= b; ++x) {
		int y = x * 1337;

		string ystr = to_string(y);
		string xstr = to_string(x);

		int matches = 0;
		for (auto c : ystr) {
			if (matches < xstr.size() && c == xstr[matches]) ++matches;
		}
		if (matches == xstr.size()) res.push_back(x);
	}
	cout << res.size() << '\n';
	for (auto v : res) cout << v << '\n';
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED