【Java】递归方法求两个字符串的最大公共子序列的长度

public class h {
    
    
    public static int f(String s1,String s2){
    
    
        if(s1.length()==0||s2.length()==0){
    
    
            return 0;
        }

        if(s1.charAt(0) == s2.charAt(0)) {
    
     return f(s1.substring(1),s2.substring(1)) +1;}
        else {
    
     return Math.max(f(s1.substring(1),s2),f(s1,s2.substring(1))); }
    }
    public static void main(String[] args){
    
    
        System.out.println(f("csdnRegan","wechatRegan"));
    }
}