C 语言中的多线程线性查找
我们在这里将看到如何应用多线程概念来搜索数组中的一个元素。这里的方法非常简单。我们将创建一些线程,然后将数组分成不同的部分。不同的线程将在不同的部分进行搜索。此后,当找到该元素时,启用标记以识别该元素。
示例
#include <stdio.h> #include <pthread.h> #define MAX 16 #define THREAD_MAX 4 int array[MAX] = { 1, 5, 7, 10, 12, 14, 15, 18, 20, 22, 25, 27, 30, 64, 110, 220 }; int key = 18; int flag = 0; //flag to indicate that item is found in the array or not int current_thread = 0; void* ThreadSearch(void* args) { //This is linear search function. It will be running using all threads int num = current_thread++; for (int i = num * (MAX / 4); i < ((num + 1) * (MAX / 4)); i++){ if (array[i] == key) flag = 1; //set flag if key is found } } int main() { pthread_t thread[THREAD_MAX]; for (int i = 0; i < THREAD_MAX; i++) { //create multiple threads pthread_create(&thread[i], NULL, ThreadSearch, (void*)NULL); } for (int i = 0; i < THREAD_MAX; i++) { pthread_join(thread[i], NULL); //wait untill all of the threads are completed } if (flag == 1) printf("Key element is found
"); else printf("Key element is not present
"); }
输出
$ gcc 1249.Thread_search.cpp -lpthread $ ./a.out Key element is found
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