#include <iostream>
#include <time.h>

using namespace std;

#define maxn 10
#define maxk 1e6 //f1、f2太小 執行時間不到一個tick 
				//clock函式捕捉不到 所以重複跑幾次  函式重複次數

double duration;
clock_t start, stop;

double f1(int n,double a[],double x)
{
	double p = a[0];
	for (int i = 0; i <=n; i++)
	{
		p += a[i] * pow(x, i);
	}
	return p;
}

double f2(int n, double a[], double x)  //秦九韶 多項式簡化演算法
{
	double p = a[n];
	for (int i = n; i >=0; i--)
	{
		p = a[i - 1] + x * p;
	}
	return p;
}

int main()
{
	double a[maxn],x=6;
	for (int i = 0; i < maxn; i++)
	{
		a[i] = i;
	}

	start = clock();
	for (int i = 0; i < maxk; i++)
	{
		f1(maxn - 1, a, x);
	}
	stop = clock();
	duration = (double)(stop - start) / CLK_TCK / maxk;
	printf("tick1=%f\n", (double)(stop - start));
	printf("dura1=%6.2e\n", duration);
	
	start = clock();
	for (int i = 0; i < maxk; i++)
	{
		f2(maxn - 1, a, x);
	}
	stop = clock();
	duration = (double)(stop - start) / CLK_TCK / maxk;
	printf("tick2=%f\n", (double)(stop - start));
	printf("dura2=%6.2e\n", duration);

	return 0;
}