记一次 c 语言 的 多线程查找 简单实现

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//仅供参考学习
#define _CRT_SECURE_NO_WARNINGS //屏蔽 vs 的a
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#include <process.h>
#include <time.h>
#include <memory.h>


//直接改 m_MAX 的值则是改变总的范围
#define m_MAX 250000 //最好是 totalThread 的整数倍



typedef struct s{
    int *begin;//每个线程其实索引地址
    int lenth;//索引长度
    int target;//need find
    int Id;//thread id
    int *flag;//线程之间通信
    int *isFind;//附加功能标记那个线程找到的
}s_t;



void find(void *p)
{
    s_t* pS = (s_t*)p;//indo

    int* cur = NULL;//need find number addres

    for (cur = pS->begin; cur != pS->begin + pS->lenth; ++cur)
    {
        if (1 == *(pS->flag))
        {
            char str[100] = { 0 };
            sprintf(str, " thread %d incapable been thread %d Preemptive\n", pS->Id, *(pS->isFind));
            printf("%s", str);
            _endthread();
        }
        if ((*cur) == pS->target)
        {
            printf(TEXT("thread %d finde \n"), pS->Id);
            printf(" %d\n", *cur);
            Sleep(10);
            *(pS->flag) = 1;
            *(pS->isFind) = pS->Id;
    
            _endthread();
        }
    }
    {//快语句 看起来 代码整洁
        char str[100] = { 0 };
        sprintf(str, " Thread %.5d is incapable \n", pS->Id, *(pS->isFind));
        printf("%s", str);
    }

    _endthread();
}


int main()
{
    srand((unsigned int)time(NULL));

    //需要寻找的源
    int array[m_MAX];

    //标志位
    int flag = 0;
    int isFind = 0;

    //随机的目标
    int target = rand() % m_MAX;
    printf("Need find number is %d \n", target);


    int totalThread = 50;

    //线程需要的信息 
    s_t s[50];    //设定线程个数    ## 这里的 50 与 totalThread 变量是相关的 要改都改
    
    int dividedDataSize = (m_MAX / totalThread);        //设定每个线程需要索引的大小 


    //随机初始化 源内的数据
    for (int j = 0; j < m_MAX; ++j) {        
        array[j] = rand()%m_MAX;
    }

    //初始化每个线程
    for (int i = 0; i < totalThread; ++i)
    {
        s[i].begin = array + (i*dividedDataSize);
        s[i].Id = i;
        s[i].lenth = (dividedDataSize);
        s[i].target = target;
        s[i].flag = &flag;
        s[i].isFind = &isFind;
        _beginthread(find, 0, &s[i]);
        Sleep(10);　　//避免出现线程访问冲突
    }


    system("pause");
    return 0;
}