题解 | #查找两个字符串a,b中的最长公共子串#

import java.util.*;
import java.math.*;

public class Main {
    public static void main(String[] args) {
        Scanner fzhinput = new Scanner(System.in);
        String zfc1 = fzhinput.nextLine();
        String zfc2 = fzhinput.nextLine();
        if(zfc1.length()<zfc2.length()){
            System.out.println(maxzfczc(zfc1, zfc2));
        }
        else{
            System.out.println(maxzfczc(zfc2, zfc1));
        }
    }
    private static String maxzfczc(String zfc1, String zfc2) {
        int len1 = zfc1.length();
        int len2 = zfc2.length();
        int maxLength = 0;  
        int endIndex = 0;   
        int[][] dp = new int[len1 + 1][len2 + 1];

        for (int i = 1; i <= len1; i++) {
            for (int j = 1; j <= len2; j++) {
                if (zfc1.charAt(i - 1) == zfc2.charAt(j - 1)) {
                    dp[i][j] = dp[i - 1][j - 1] + 1;
                    if (dp[i][j] > maxLength) {
                        maxLength = dp[i][j];
                        endIndex = i;
                    }
                }
            }
        }

        return zfc1.substring(endIndex - maxLength, endIndex);
    }

}