#include <iostream.h>
#include <stdlib.h>

long Fib(int n)
{
	if(n == 0 || n == 1) return n;		//遞歸出口
	else return Fib(n-1) + Fib(n-2);	//遞歸調用
}

/*
long Fib(int n)
{
	if(n == 0 || n == 1) return n;
	else
	{
		long int oneBack = 1, twoBack = 0, current;
		for(int i = 2; i <= n; i++)
		{
			current = oneBack + twoBack;
			twoBack = oneBack;
			oneBack = current;
		}
		return current;
	}
}
*/
void main(void)
{
	int n;
	cout << "輸入要計算的斐波那契數列的項數n: ";
	cin >> n;

	if(n < 1)
	{
		cout << "參數出錯!";
		exit(1);
	}
	cout << "Fib(n) = " << Fib(n) << endl;
}