# LeetCode:Is Subsequence

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`.

``````public class Solution {
public boolean isSubsequence(String s, String t) {
if (s.length() == 0) return true;
int indexS = 0, indexT = 0;
while (indexT < t.length()) {
if (t.charAt(indexT) == s.charAt(indexS)) {
indexS++;
if (indexS == s.length()) return true;
}
indexT++;
}
return false;
}
}``````

``````public class Solution
{
public boolean isSubsequence(String s, String t)
{
if(t.length() < s.length()) return false;
int prev = 0;
for(int i = 0; i < s.length();i++)
{
char tempChar = s.charAt(i);
prev = t.indexOf(tempChar,prev);
if(prev == -1) return false;
prev++;
}

return true;
}
}``````