// [문제 링크]: https://school.programmers.co.kr/learn/courses/30/lessons/147355 import java.util.stream.LongStream; class Solution { public int solution(String t, String p) { long targetNumber = Long.parseLong(p); int targetNumberLength = p.length(); return (int) LongStream.range(0L, t.length() - targetNumberLength + 1L) .mapToObj(i -> t.substring((int) i, (int) i + targetNumberLength)) .mapToLong(Long::parseLong) .filter(number -> number <= targetNumber) .count(); } }