Day025 - 392. Is Subsequence

392. Is Subsequence

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 <= 104
• s and t consist only of lowercase English letters.

Follow up: Suppose there are lots of incoming s, say s1, s2, ..., sk where k >= 109, and you want to check one by one to see if t has its subsequence. In this scenario, how would you change your code?

내 풀이

class Solution:
    def isSubsequence(self, s: str, t: str) -> bool:
        from collections import deque

        s = deque(s)
        t = deque(t)

        while t:
            if not s: return True

            check_s = s[0]

            while t:
                if check_s == t[0]:
                    s.popleft()
                    t.popleft()
                    break
                t.popleft()

        if not s: return True
        return False

# Time Complexity : \(O(N)\)