Is Subsequence | Leetcode 392 solution

 392. Is Subsequence | Leetcode easy solution

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).

 

Example 1:

Input: s = "abc", t = "ahbgdc"
Output: true

Example 2:

Input: s = "axc", t = "ahbgdc"
Output: false

 

Constraints:

• 0 <= s.length <= 100
• 0 <= t.length <= 104
• s and t consist only of lowercase English letters.

Solution : 

class Solution { public:     bool solve(string s , string t , int i , int j)     {         if(i == -1)         {           return true;         }         if(j == -1)         {             return false;         }         if(s[i] == t[j])         {             return solve(s , t , i-1 , j-1) ;         }         return solve(s , t , i , j-1);     }     bool isSubsequence(string s, string t) {         int i = s.length() -1;         int j = t.length() -1;         return solve(s , t , i , j);           } };