Longest Common Subsequence

Given two strings text1 and text2, return the length of their longest common subsequence (LCS). If there is no common subsequence, return 0.

A subsequence is a sequence derived from a string by deleting some characters (or none) without changing the relative order of the remaining characters.

A common subsequence is a subsequence that appears in both strings.

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Example 1

Input: text1 = "abcde", text2 = "ace"
Output: 3
Explanation: The longest common subsequence is "ace", which has length 3.

Example 2

Input: text1 = "abc", text2 = "abc"
Output: 3
Explanation: The strings are identical so the LCS is "abc" itself, length 3.

Example 3

Input: text1 = "abc", text2 = "def"
Output: 0
Explanation: No character appears in both strings, so there is no common subsequence.

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Constraints

• 1 <= text1.length, text2.length <= 1000
• text1 and text2 consist of only lowercase English letters