题解 | #最长公共子串#

import java.util.*;


public class Solution {
    public String LCS (String str1, String str2) {
        int m = str1.length(), n = str2.length();
        int[][] dp = new int[m+1][n+1];
        int end = -1,max_len = 0;
        dp[0][0] = 0;
        for(int i = 1; i <= m; i++){
            for(int j = 1; j <= n; j++){
                if(str1.charAt(i-1) == str2.charAt(j-1)){
                    dp[i][j] = dp[i-1][j-1] + 1;
                    if(dp[i][j] > max_len){
                        max_len = dp[i][j];
                        end = i;
                    }
                }
            }
        }
        return str1.substring(end - max_len,end);
    }
       
}