面试题9—斐波那列数列

题目：

f(n)=

0;(n=0)

1;(n=1)

f(n-1)+f(n-2);(n>1)

代码示例：

#include<iostream>using namespace std;long long Fabi(int n){if (n == 0)return 0;if (n == 1)return 1;long long pre1 = 1;long long pre2 = 0;long long current = pre1 + pre2;for (int i = 0; i < n - 1; i++){current = pre1 + pre2;pre2 = pre1;pre1 = current;}return current;}void main(){int n = 50;long long result = Fabi(n);cout << "result:" << result << endl;}