题目 1257: 超级楼梯

题目描述:

有一楼梯共M级，刚开始时你在第一级，若每次只能跨上一级或二级，要走上第M级，共有多少种走法？

代码:

package lanqiao;

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        for (int i = 0; i < n; i++)
        {
            int m = sc.nextInt();
            System.out.println(f(m - 1));
        }
    }

    public static int f(int n)
    {
        if(n == 1) return 1;
        if(n == 2) return 2;

        int a = 1;
        int b = 2;
        int temp = 0;
        for(int i = 3;i <= n;i ++)
        {
            temp = a + b;
            a = b;
            b = temp;
        }
        return temp;
    }
}