java -- 获取两个字符串中最大相同的子串

package com.jiuwan.java;

/**
 * @author jiuwan
 * @create 2022-09-07-14:13
 */
public class Demo02 {
    public static void main(String[] args) {
        System.out.println(findBigSameString("sdfakhellossddlabcjfaaa",
                "abcdskaskldhelloass"));
    }

    //获取两个字符串中最大相同的子串
    //例如：str1 = "sdfakhellossddlabcjfaaa", str2 = "abcdskaskldhelloass"
    public static String findBigSameString(String str1, String str2){
        //确保str1的长度大于str2的长度
        if(str1.length() < str2.length()){
            String  temp = str1;
            str1 = str2;
            str2 = temp;
        }

        String result = null;
/*        //从最小长度开始比较，比较的次数更多
        int count = 0;
        for (int  i = 0; i < str2.length(); i++) {
            for (int j = 0; j < str2.length() - i; j++) {
                count++;
                String tempStr = str2.substring(j, j + 1 + i);
                if (str1.contains(tempStr)
                        && (result == null || tempStr.length() > result.length())){
                    result = tempStr;
                }
            }
        }*/

        //从最大长度开始比较，比较的次数更少
        int count = 0;
        for (int  i = str2.length() - 1; i >= 0; i--) {
            for (int j = 0; j < str2.length() - i; j++) {
                count++;
                //截取短的那个字符串进行长度依次递减的子串与较长的字符串进行比较
                String tempStr = str2.substring(j, j + i + 1);
                if (str1.contains(tempStr)
                        && (result == null || tempStr.length() > result.length())){
                    result = tempStr;
                    System.out.println("循环次数：" + count);
                    //因为一旦找到就可以退出该方法了
                    return result;
                }
            }
        }
        return result;
    }
}