Given a string s and a string t, check if s is subsequence of t.

Problem: Given a string s and a string t, check if s is subsequence of t.

Example:

Input: s = "nsa", t = "nishant"
Output: true

Input: s = "nas", t = "nishant"
Output: false

Approach: It's a straight forward problem to solve. Solution can be easily understood by just looking at the code.

Implementation in C#:

        public bool IsSubsequence(string s, string t)

        {

            int sItr = 0, tItr = 0;

            while (sItr < s.Length && tItr < t.Length)

            {

                if (s[sItr] == t[tItr])

                {

                    ++sItr;

                }

                ++tItr;

            }

            return sItr == s.Length;

        }

Complexity: O(n)