392. Is Subsequence

Is Subsequence

Problem

Description

Given a string s and a string t, check if s is subsequence of t.

You may assume that there is only lower case English letters in both s and t. t is potentially a very long (length ~= 500,000) string, and s is a short string (<=100).

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

Example

s = "abc", t = "ahbgdc"
Return true.


s = "axc", t = "ahbgdc"
Return false.

Solution

Approach1

Approach2