剑指Offer之 - 斐波那契数列

来源：互联网发布：什么是淘宝店铺运营编辑：程序博客网时间：2024/05/16 10:02

题目：

应用：

青蛙跳台阶，爬楼梯，小矩形覆盖大矩形……

思路：

1、递归

2、迭代

代码：

#include <iostream>using namespace std;//斐波那契数列//应用：青蛙跳台阶，爬楼梯，小矩形覆盖大矩形long long fibonacciRecurisely(int n){if(n == 0 || n == 1)return n;return fibonacciRecurisely(n-1) + fibonacciRecurisely(n-2);}//何海涛做法long long Fibonacci(unsigned n){int result[2] = {0,1};if(n < 2)return result[n];long long fibNMinusOne = 0;long long fibNMinusTwo = 1;long long fibN = 0;for(unsigned int i = 2 ; i <= n ; i++){fibN = fibNMinusOne + fibNMinusTwo;fibNMinusOne = fibNMinusTwo;fibNMinusTwo = fibN;}return fibN;}long long fibonacciInteratively(int n){long long pre = 0;long long result = 1;if(n <= 1)return n;long long tmp = result;for(int i = 2 ; i <= n ; i++){tmp = result;result += pre;pre = tmp;}return result;}//矩阵方法，不会int main(){int x ;while(cin>>x){cout<<fibonacciRecurisely(x)<<endl;//当数据很大时，递归速度明显变慢很多cout<<fibonacciInteratively(x)<<endl;cout<<Fibonacci(x)<<endl;}}

0 0