392. Is Subsequence

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

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.

Approach

Solution

class Solution:
    def isSubsequence(self, s: str, t: str) -> bool:
        if len(s) > len(t):
            return False

        i, j = 0, 0
        while i < len(s) and j < len(t):
            if s[i] == t[j]:
                i += 1
            j += 1

        return i == len(s)

Explanation