Fri. Mar 29th, 2024

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 tt 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 1:
s = "abc"t = "ahbgdc"

Return true.

Example 2:
s = "axc"t = "ahbgdc"

Return false.

class Solution {
    public boolean isSubsequence(String s, String t) {
        char[] s_array = s.toCharArray();
        int previndex = -1;
        int j=0;
        for(int i=0;i<t.length();i++){
           if(j==s.length()) return true;
           if(t.charAt(i) == s.charAt(j)) j++; 
        }
        
        return j==s.length();
    }
}