#include<omp.h>
#include<iostream>
#include<random>
using namespace std;

void sapxep(int a[] ,int n )
{
        for(int i = 0; i < n-1; i++){
            for(int j = i+1; j< n; j++){
                if(a[i] > a[j]){
                    swap(a[i], a[j]);
                }
            }
        }
}

void sapxepss(int a[] ,int n )
{
    #pragma omp paralell for num_threads(4)
    for(int i = 0; i < n-1; i++){
        for(int j = i+1; j< n; j++){
            if(a[i] > a[j]){
                swap(a[i], a[j]);
            }
        }
    }
}

void sapxepsss(int a[] ,int n )
{
    for(int i = 0; i < n; i++){
        if(i % 2 == 0){
            #pragma omp paralell for
            for(int j= 0; j < n-1; j+=2){
                if(a[i] > a[j]) swap(a[i], a[j]);
            }
        }else{
            #pragma omp paralell for
            for(int j= 1; j < n-1; j+=2){
                if(a[i] > a[j]) swap(a[i], a[j]);
            }
        }
    }
}


void xuat(int *a[] ,int n){
    for(int i = 0; i < n;i++){
        cout << " " << a[i];
    }
}

int main()
{
    cout << "nhap so luong phan tu: ";
    int n;
    cin >> n;
    int *a = new int[n];
    int *b = new int[n];
    int *c = new int[n];

    for(int i=0; i<n; i++){
        a[i] = rand();
        b[i] = a[i];
        c[i] = a[i];
    }
    double t1= omp_get_wtime();
    sapxep(a, n);
    double t2 = omp_get_wtime();
    sapxepss(b, n);
    double t3 = omp_get_wtime();
    sapxepsss(c, n);
    double t4 = omp_get_wtime();

    cout << "chay binh thuong " << t2-t1 << endl;
    cout << "chay song song " << t3-t2 << endl;
    cout << "chay song song song " << t4-t3 << endl;
    delete[] a;
    delete[] b;
    return 0;
}