20.斐波那契数列

• 题目描述

大家都知道斐波那契数列，现在要求输入一个整数n，请你输出斐波那契数列的第n项（从0开始，第0项为0，第1项是1）。

n<=39

• 思路

和跳台阶类似

https://blog.youkuaiyun.com/gtjsjj/article/details/106707272

• 代码

public class Solution {
    public int Fibonacci(int n) {
        if(n == 0)
            return 0;
        if(n == 1)
            return 1;
        int one = 0;
        int two = 1;
        int three = 0;
        for(int i = 2; i <= n; i++){
            three = one + two;
            one = two;
            two = three;
        }
        return three;
    }
}