算法之斐波纳契数列

#include <stdio.h>using namespace std;int fibonacci_recursive(int a){    int sum;    if(a <= 0)                    return -1;    else if((a == 1) || (a == 2)) return 1;    else                          sum = fibonacci_recursive(a-1) + fibonacci_recursive(a-2);    return sum;}int fibonacci_nonRecursive(int n){    int i, s = 0, s1, s2;    s1 = 1, s2 =1;    for(i = 3; i <= n; i++)    {        s=s1+s2;        s1=s2;        s2=s;    }    return s;}void main(){    printf("%d\n", fibonacci_recursive(6));    printf("%d\n", fibonacci_nonRecursive(6));}