两个字符串的最长公共子串

动态规划

package com.String;

public class zichuan {
    public static void main(String[] args) {
        String s1="1AB2345CD";
        String s2="12345EE";
        System.out.println(LCS(s1,s2));
    }
    public static String LCS(String s1,String s2){
        int maxLenth=0;//最长公共子串的长度
        int maxLastIndex=0;//最长公共子串最后一个元素在s1中的位置
        int[][] dp=new int[s1.length()+1][s2.length()+1];
        for (int i = 0; i < s1.length(); i++) {
            for (int j = 0; j < s2.length(); j++) {
                if (s1.charAt(i)==s2.charAt(j)){//两个字符相等
                    dp[i+1][j+1]=dp[i][j]+1;
                    if (dp[i+1][j+1]>maxLenth){
                        maxLenth=dp[i+1][j+1];
                        maxLastIndex=i;
                    }
                }
                else {//字符不相等
                    dp[i+1][j+1]=0;
                }
            }
        }
        return s1.substring(maxLastIndex-maxLenth+1,maxLastIndex+1);

    }

}