题解 | #查找两个字符串a,b中的最长公共子串# 动态规划

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String a = in.nextLine();
        String b = in.nextLine();
        if(a.length()>b.length()) {
            String c = a;
            a = b;
            b = c;
        }
        char[]A = a.toCharArray();
        char[]B = b.toCharArray();
        int[][]arr = new int[A.length+1][B.length+1];
        int maxLen = 0, endIndex = 0;
        for(int i=1;i<=A.length;i++) {
            for(int j=1;j<=B.length;j++) {
                if(A[i-1]==B[j-1]) {
                    arr[i][j] = arr[i-1][j-1] + 1;
                    if(maxLen<arr[i][j]) {
                        maxLen = arr[i][j];
                        endIndex = i;
                    }
                } else {
                    arr[i][j] = 0;
                }
            }
        }
        System.out.println(a.substring(endIndex-maxLen, endIndex));
    }
}