不一样的青蛙跳台阶

Posted 2022-10-15 王六六同学

之前遇到的青蛙是跳1层或2层，这个青蛙是1层、2层、3层的跳

import java.util.Scanner;

/**
 * @author WanZi
 * @create 2022-10-11 19:35
 */
//1层、2层、3层
public class Main 
    public static void main(String[] args) 
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        int res = skip(N);
        System.out.println(res);
    

    public static int skip(int n)
        if(n == 1)
            return 1;
        
        if(n == 2)
            return 2;
        
        if(n == 3)
            return 4;
        
        int[] dp = new int[n+1];
        dp[0] = 1;
        dp[1] = 1;
        dp[2] = 2;
        for(int i=3;i<=n;i++)
            dp[i] = dp[i-1] + dp[i-2] + dp[i-3];
        
        return dp[n];