剑指Offer07 斐波那契数列

/*************************************************************************
    > File Name: 07_Fibonacci.c
    > Author: Juntaran
    > Mail: JuntaranMail@gmail.com
    > Created Time: 2016年08月29日 星期一 20时23分54秒
 ************************************************************************/

#include <stdio.h>

long long Fibonacci1(int n)
{
    if (n <= 0)
        return 0;
    if (n == 1)
        return 1;
    return Fibonacci1(n-2) + Fibonacci1(n-1);
}

long long Fibonacci2(int n)
{
    int result[2] = {0, 1};
    if (n < 2)
        return result[n];
    
    long long fibNum1 = 0;
    long long fibNum2 = 1;
    long long temp = 0;
    
    for (int i = 2; i <= n; ++i)
    {
        temp = fibNum1 + fibNum2;
        fibNum1 = fibNum2;
        fibNum2 = temp;
    }
    return temp;
}

int main()
{
    int n = 100;
    long long ret1, ret2;
    ret1 = Fibonacci1(n);
    ret2 = Fibonacci2(n);
    printf("ret1 is %lld, ret2 is %lld
", ret1, ret2);
}