1143. Longest Common Subsequence

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

A subsequence of a string is a new string generated from the original string with some characters (can be none) deleted without changing the relative order of the remaining characters.

• For example, “ace” is a subsequence of “abcde”.
  A common subsequence of two strings is a subsequence that is common to both strings.

class Solution {
public:
    int longestCommonSubsequence(string text1, string text2) {
        vector<vector<int>> dp(text1.size() + 1, vector<int>(text2.size() + 1));
        for(int i = 1; i <= text1.size(); i++) {
            for(int j = 1; j <= text2.size(); j++) {
                if(text1[i-1] == text2[j-1]) dp[i][j] = 1 + dp[i-1][j-1];
                else dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
            }
        }
        return dp[text1.size()][text2.size()];
    }
};