Is Subsequence

Problem Statement:

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 1:
s = "abc", t = "ahbgdc"
Return true.

Example 2:
s = "axc", t = "ahbgdc"
Return false.



Solution:
class Solution:
    def isSubsequence(self, s: str, t: str) -> bool:
        i=0
        j=0
        cnt=0
        while i<=len(s)-1 and j<=len(t)-1:
            if s[i]==t[j]:
                cnt+=1
                i+=1
                j+=1
            else:
                j+=1
            
        return cnt==len(s)