LeetCode 392. 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
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

.

class Solution {
public:
bool isSubsequence(string s, string t) {
int i=0,j=0;
while(i<s.size() && j<t.size()){
if(s.at(i)==t.at(j)){
i++;
j++;
}else{
j++;
}
}
if(i<s.size()){
return false;
}else{
return true;
}
}
};