Given two strings str1 and str2 of lengths m and n respectively (m≤n), find whether str1 is a subsequence of str2
Examples:
Input: str1 = "axy", str2 = "abcxjhy"
Output: true
If length of lcs(str1,str2) = length of str1 then return true else return false
https://www.youtube.com/watch?v=QVntmksK2es&list=PL_z_8CaSLPWekqhdCPmFohncHwz8TY2Go&index=32&ab_channel=AdityaVerma
Time and Space Complexity of the above implementation is O(m*n)