1143 Longest Common Subsequence

Given two strings text1 and text2, return the length of their longest common subsequence.

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. (eg, "ace" is a subsequence of "abcde" while "aec" is not). A common subsequence of two strings is a subsequence that is common to both strings.


If there is no common subsequence, return 0.

 

Example 1:

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


public int longestCommonSubsequence(String text1, String text2) {
       int[][] dp = new int[text1.length()+1][text2.length()+1];
        
       for(int i=1;i<dp.length;i++){
           for(int j=1;j<dp[0].length;j++){
               if(text1.charAt(i-1)==text2.charAt(j-1)){
                   dp[i][j] = dp[i-1][j-1]+1;
               }else{
                    dp[i][j] = Math.max(dp[i][j-1],dp[i-1][j]);
               }
           }
       }     
       return dp[text1.length()][text2.length()];
    }