CodeParkReturn the length of the longest common subsequence of two strings a and b.
A subsequence is what's left after you delete zero or more characters. The remaining characters keep their order. For example, "rve" is a subsequence of "brave", but "evr" is not. A common subsequence appears in both strings.
- Either string may be empty. Then the answer is
0. - Each string has up to 1,000 lowercase letters.
- Return only the length, not the subsequence itself.
Input: a = "brave", b = "bread"
Output: 3"bra" is in both strings. So is "bre". No common subsequence of length 4 exists.
Input: a = "abc", b = "cba"
Output: 1
Input: a = "drill", b = ""
Output: 0