多线程并行计算数据总和 —— 优化计算思想（多线程去计算）—— C语言demo

#include <stdio.h>
#include <stdlib.h>
#include <Windows.h>
#include<process.h>
#include <time.h>
#define N 1024

struct Myinfo
{
int *pstart;//开始地址
int length;//长度
int id;//线程编号
int sum;//存储数据的和
};
void  add(void *p) //void *p可以保存任何类型的指针
{
struct Myinfo *pinfo = p;
for (int i = 0; i < pinfo->length;i++)
{
pinfo->sum += pinfo->pstart[i];
}
printf("\n线程%d计算的结果%d", pinfo->id, pinfo->sum);
}

void main()
{
time_t ts;
unsigned int num = time(&ts);//传递地址
srand(num);
int data
= { 0 };
　　 // 进行赋值
for (int i = 0; i < N; i++)
{
data[i] = rand() % 1000;
//printf("%4d", data[i] = rand() % 1000);
}
int sum = 0;
　　 //计算总和
for (int i = 0; i < N; i++)
{
sum += data[i];
}
printf("\n总和=%d", sum);

struct Myinfo info[8] = { 0 };
for (int i = 0; i < 8;i++)
{
info[i].id = i;
info[i].length = N / 8;
info[i].sum = 0;
info[i].pstart = data + i*N / 8; //注意这里地址的移动
_beginthread(add, 0, &info[i]);
}
system("pause");

int lastsum=0;
for (int i = 0; i < 8;i++)
{
lastsum += info[i].sum;
}
printf("\n多线程总和=%d", lastsum);
system("pause");
}