[LeetCode] 392. Is Subsequence - 문제풀이

Description

두 문자열 s와 t가 주어졌을 때 s가 t의 연속이면 true를 반환하고 그렇지 않으면 false를 반환한다.

Given two strings s and t, return true if s is a subsequence of t, or false otherwise.

A subsequence of a string is a new string that is formed from the original string by deleting some (can be none) of the characters without disturbing the relative positions of the remaining characters. (i.e., "ace" is a subsequence of "abcde" while "aec" is not).

Example 1:

Input: s = "abc", t = "ahbgdc"
Output: true

Example 2:

Input: s = "axc", t = "ahbgdc"
Output: false

Constraints:

• 0 <= s.length <= 100
• 0 <= t.length <= 10^4
• s and t consist only of lowercase English letters.

Follow up:

Suppose there are lots of incoming

has its subsequence. In this scenario, how would you change your code?

Solution 1. Two pointer

public boolean isSubsequence(String s, String t) {
    if(s.length() == 0) return true;
    int i = 0;
    for (int j = 0; j < t.length(); j++) {
        if(s.charAt(i) == t.charAt(j)){
            if(++i==s.length()) return true;
        }
    }
    return false;
}

두 개의 포인터를 이용하여 일치할 경우 s포인터를 하나씩 이동하고 s의 포인터가 마지막까지 이동했다면 true를 아니면 false를 반환합니다.

Reference