第一章 起步——串行程序

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/JennyBi/article/details/81276645

dist_v1/main.cpp

#include <math.h>
#include "stdlib.h"
#define N 64

float scale(int i, int n)
{
	return ((float)i / (n - 1));
}

float distance(float x1, float x2)
{
	return sqrt((x2 - x1)*(x2 - x1));
}

int main()
{
	float out[N] = { 0.0f };
	const float ref = 0.5f;

	for (int i =0;i<N;i++)
	{
		float x = scale(i, N);
		out[i] = distance(x, ref);
	}
	system("pause");
	return 0;
}

dist_v2/main.cpp

#include "aux_function.h"
#include <stdlib.h>
#define N 20000000

int main()
{
// 	float in[N] = { 0.0f };
// 	float out[N] = { 0.0f };
	float *in = (float*)calloc(N, sizeof(float));
	float *out = (float*)calloc(N, sizeof(float));



	const float ref = 0.5f;
	for (int i =0; i<N; i++)
	{
		in[i] = scale(i, N);
	}
	distanceArray(out, in, ref, N);

	free(in);
	free(out);
	return 0;
}

dist_v2/aux_function.h

#pragma once

float scale(int i, int n);

float distance(float x1, float x2);

void distanceArray(float *out, float *in, float ref, int N);

dist_v2/aux_function.cpp

#include "aux_function.h"
#include <math.h>

float scale(int i, int n)
{
	return ((float)i / (n - 1));
}

float distance(float x1, float x2)
{
	//return sqrt((x2-x1)*(x2 - x1));
	return fabsf(x1 - x2);
}

void distanceArray(float *out, float *in, float ref, int n)
{
	for (int i = 0; i<n ; i++)
	{
		out[i] =distance(in[i],ref) ;
	}
}