June 29th 2023

Problem Description permalink

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).

Solution permalink

function isSubsequence(s: string, t: string): boolean {
    let currentLetter = 0;
    for (var i=0; i<t.length; i++){
        if (t[i] === s[currentLetter]){
            currentLetter += 1
        }
    }

    return s.length === currentLetter
};