斐波那契数列 打印，求和

// stl1-9-5.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <cstdlib>
#include <iostream>

using namespace std;

int fib2(int n);
int fib(int n);

const int gconst = 20;
int _tmain(int argc, _TCHAR* argv[])
{
// 打印数列前gconst项 ==
int ia[gconst] = { 0x0 };

cout << "第一种比较直观的方法：" << endl;
ia[0] = 0;
ia[1] = 1;
for (int i = 2; i < gconst; i++)
{
ia[i] = ia[i - 2] + ia[i - 1];	   // 保存数列 ==
}

for (int i = 0; i < gconst; i++)
{
cout << ia[i] << " ";			   // 打印数列 ==
}

cout << endl;
cout << "用另一种方法输出数列：" <<endl;

for (int i = 0; i < gconst; i++)
{
ia[i] = fib(i);					   // 保存数列 ==
}

for (int i = 0; i < gconst; i++)
{
cout << ia[i] << " ";			   // 打印数列 ==
}

cout << endl;

for (int i = 0; i < gconst; i++)
{
cout << ia[i] << " ";
}
cout << endl;

long sum = 0;
for (int i = 0; i < gconst; i++)
{
sum += ia[i];					// 求和 ==
}

cout << sum << " ";
cout << endl;

return 0;
}
// 输出数列值 ==
int fib2(int n)
{
if (n == 0)
return 0;
if (n == 1)
return 1;
return fib2(n - 1) + fib2(n - 2);
}

// 输出数列值 ==
int fib(int n)
{
int result[2] = { 0, 1 };
if (n < 2)
return result
;
int fibOne = 0;
int fibTwo = 1;
int fibN = 0;
int i = 0;
for (i = 2; i <= n; i++)
{
fibN = fibOne + fibTwo;

fibOne = fibTwo;
fibTwo = fibN;
}

return fibN;
}