#include <iostream> #define MAX 16 #define MAX_THREAD 4 using namespace std; //place arr, key and other variables as global to access from different thread int arr[] = { 1, 6, 8, 11, 13, 14, 15, 19, 21, 23, 26, 28, 31, 65, 108, 220 }; int key = 31; bool found = false; int part = 0; void* binary_search(void* arg) { // There are four threads, each will take 1/4th part of the list int thread_part = part++; int mid; int start = thread_part * (MAX / 4); //set start and end using the thread part int end = (thread_part + 1) * (MAX / 4); // search for the key until low < high // or key is found in any portion of array while (start < end && !found) { //if some other thread has got the element, it will stop mid = (end - start) / 2 + start; if (arr[mid] == key) { found = true; break; } else if (arr[mid] > key) end = mid - 1; else start = mid + 1; } } main() { pthread_t threads[MAX_THREAD]; for (int i = 0; i < MAX_THREAD; i++) pthread_create(&threads[i], NULL, binary_search, (void*)NULL); for (int i = 0; i < MAX_THREAD; i++) pthread_join(threads[i], NULL); //wait, to join with the main thread if (found) cout << key << " found in array" << endl; else cout << key << " not found in array" << endl; }

输出

31 found in array