//我是写了一个在1000000个int类型的数组用100个线程去查找数据

#include<stdio.h>
#include<stdlib.h>
#include<Windows.h>
#include<time.h>
#include<process.h>

#define SIZE 1000000                      //动态数组的大小
extern int flag;                          //是否找到的标识符，找到是0，没有是1

typedef struct Large_data                //定义一个结构体为线程传递信息
{
    int order;                           //线程的编号
    int* pstart;                          //每个线程开始查找的地址
    int length;
    int* pflag;                            //存储标识符的地址，好改变标识符的值
    int num;                               //需要查找的数据
}Large_data;


void Large_find(void* p);                    //查找数据的函数

void ppfind(int* p,int num)                    //不开启线程查找的函数
{
    for (int i = 0; i < SIZE; i++)
    {
        if (p[i] == num)
        {
            printf("找到了%d\n",p[i]);
            return;
        }
    }
}
int main()
{
    int* plarge = (int*)calloc(SIZE, sizeof(int));                  //动态申请存储1000000个int类的数据
    if (!plarge)
    {
        printf("分配失败");
        exit(1);
    }
    printf("%p\n", plarge);
    int i = 1;
    for (int* p = plarge; p < plarge + SIZE; p++)                   //为动态数组赋初值
        *p = i++;
    Large_data Data[100];                                          //创建有100个结构体数组为100个线程传递信息
    DWORD start = GetTickCount();                                  // 记录开始线程的时间
    for (int i = 0; i < 100; i++)                                 //开启100个线程
    {
        
        Data[i].pstart = plarge + 10000*i;                         //让每一个线程在10000个数据中查找
        Data[i].length = 10000;                                    //确定每一个线程查找的长度
        Data[i].num = 10000;                                       //为每一个线程传递需要查找的数据
        Data[i].order = i;                                   
        Data[i].pflag = &flag;
        _beginthread(Large_find, 0, &Data[i]);
        //Sleep(100);
    }
    /*clock_t start = 0, end = 0;
    double cpu_time = 0.0;
    start = clock();*/
   
    //ppfind(plarge, 100000);
    Sleep(100);
    DWORD end = GetTickCount();                                  //记录线程结束的时间
    //end = clock();

    //cpu_time =(double) (end - start) / CLOCKS_PER_SEC;
    //printf("%lf", cpu_time);
    printf("%ld", end - start);                             //打印所花的时间
    free(plarge);
    plarge = NULL;
    getchar();
    return 0;
}

void Large_find(void* p)
{
    Large_data* pdata = (Large_data*)p;
    for (int* ptemp = pdata->pstart; ptemp < pdata->pstart + pdata->length; ptemp++)             //遍历10000个数据查找所需要找的数据
    {
        //Sleep(10);发现只要在这里添加休眠10ms函数就会内存冲突
        if (flag == 0)                                         //检测其他线程是否找到，找到就退出循环
        {
            printf("线程%d,没有找到\n", pdata->order);
            return;
        }
        if (*ptemp == pdata->num)                             //如果找到，就改变标识符，好让其他线程退出查找
        {
            *(pdata->pflag) = 0;
            printf("线程%d的，找到%d了\n", pdata->order, *ptemp);
            return;
        }

    }
}

多谢楼主，