1 /**
 2  * @author: wooch
 3  * @create: 2020/02/12
 4  *
 5  * 最长公共子序列
 6  * 核心思路：
 7  * 首先子序列是非连续性的，因此两个字符串的 最长公共子序列 必然是以两个字符串最先相同的字符开始计算
 8  * 因此以此为基础进行递归
 9  */
10 public class LongestPublicSubSequence {
11     public static void main(String[] args) {
12         int a = longestPublicSubSequence("abcd","xacdb");
13         System.out.println(a);
14     }
15 
16     /**
17      * by recursive
18      * @param strX
19      * @param strY
20      * @return
21      */
22     public static int longestPublicSubSequence(String strX,String strY){
23         if(strX.length()==0||strY.length()==0){
24             return 0;
25         }
26         if(strX.charAt(0)==strY.charAt(0)){
27             return longestPublicSubSequence(strX.substring(1),strY.substring(1))+1;
28         }else{
29             return Math.max(longestPublicSubSequence(strX.substring(1),strY),
30                     longestPublicSubSequence(strX,strY.substring(1)));
31         }
32     }
33 }