cpp/heapsort.cpp at master · priyanshu1044/cpp · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
#include <iostream>
using namespace std;

void heap(int arr[], int n, int i)
{
    int largest = i;
    int l = 2 * i + 1;
    int r = 2 * i + 2;

    if (l < n && arr[l] > arr[largest])
        largest = l;

    if (r < n && arr[r] > arr[largest])
        largest = r;

    if (largest != i)
    {
        swap(arr[i], arr[largest]);
        heap(arr, n, largest);
    }
}

void heapSort(int arr[], int n)
{
    for (int i = n / 2 - 1; i >= 0; i--)
        heap(arr, n, i);

    for (int i = n - 1; i > 0; i--)
    {
        swap(arr[0], arr[i]);
        heap(arr, i, 0);
    }
}

void printArray(int arr[], int n)
{
    for (int i = 0; i < n; ++i)
        cout << arr[i] << " ";
    cout << "\n";
}

int main()
{
    int num;
    cin >> num;
    int arr[num];
    for (int i = 0; i < num; i++)
    {
        cin >> arr[i];
    }
    int n = sizeof(arr) / sizeof(arr[0]);

    heapSort(arr, n);
    printArray(arr, n);
}