题解 | #查找两个字符串a,b中的最长公共子串#

这道题不是子序列,所以用两个for循环, 利用String的contain 比较即可.

注意要区分哪个是长字符串,那个是短的字符串,因为可能有多个子字符相同长度

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);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextLine()) { // 注意 while 处理多个 case
            String a = in.nextLine();
            String b = in.nextLine();


            String shortOne = a.length() > b.length() ? b : a;
            String longOne = a.length() < b.length() ? b : a;


            MaxSub maxSub = new MaxSub(0, "");

            for (int i = 0; i < shortOne.length(); i++) {
                for (int j = i + 1; j <= shortOne.length(); j++) {
                    String substring = shortOne.substring(i, j);
                    if (longOne.contains(substring)) {
                        if (maxSub.len < substring.length()) {
                            maxSub.len = substring.length();
                            maxSub.subString = substring;
                        }
                    }
                }
            }

            System.out.println(maxSub.subString);
        }
    }

    public static class MaxSub {
        int len;
        String subString;

        public MaxSub(int len, String subString) {
            this.len = len;
            this.subString = subString;
        }
    }

}