基于 OpenMP 的奇偶排序算法的实现

代码：

#include <omp.h>
#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

const int NUM = 8000;
const int MAX = 1000000;
const int MIN = 0;
const int NUM_THREADS = 8;

int arr[NUM];

int main() {
    cout << "Odd-even transportion sort start..." << endl;
    cout << "Generate random data... ";
    memset(arr, 0, NUM * sizeof(arr[0]));
    srand(time(NULL));
    omp_set_num_threads(NUM_THREADS);
#pragma omp parallel for
    for (int i = 0; i < NUM; i++) {
        arr[i] = MIN + rand() % (MAX - MIN);
    }
    cout << "Done." << endl;
    cout << "Sorting... ";
    for (int i = 0; i < NUM; i++) {
        if (i % 2 == 0) {
#pragma omp parallel for
            for (int j = 0; j < NUM - 1; j += 2) {
                if (arr[j] > arr[j + 1]) {
                    int temp = arr[j];
                    arr[j] = arr[j + 1];
                    arr[j + 1] = temp;
                }
            }
        } else {
#pragma omp parallel for
            for (int j = 1; j < NUM - 1; j += 2) {
                if (arr[j] > arr[j + 1]) {
                    int temp = arr[j];
                    arr[j] = arr[j + 1];
                    arr[j + 1] = temp;
                }
            }
        }
    }
    cout << "Done." << endl;
    cout << "Result:" << endl;
    int counter = 1;
    int row = 20;
    for (int i = 0; i < NUM; i++,counter++) {
        cout << arr[i] << " ";
        if (counter % row == 0) cout << endl;
    }
}

截图：