1#include <stdio.h>
2
3void merge(int arr[], int l, int m, int r) {
4    int i, j, k;
5    int n1 = m - l + 1;
6    int n2 = r - m;
7    int L[n1], R[n2];
8    for (i = 0; i < n1; i++)
9        L[i] = arr[l + i];
10    for (j = 0; j < n2; j++)
11        R[j] = arr[m + 1 + j];
12    i = 0;
13    j = 0;
14    k = l;
15    while (i < n1 && j < n2) {
16        if (L[i] <= R[j]) {
17            arr[k] = L[i];
18            i++;
19        }
20        else {
21            arr[k] = R[j];
22            j++;
23        }
24        k++;
25    }
26    while (i < n1) {
27        arr[k] = L[i];
28        i++;
29        k++;
30    }
31    while (j < n2) {
32        arr[k] = R[j];
33        j++;
34        k++;
35    }
36}
37
38void mergeSort(int arr[], int l, int r) {
39    if (l < r) {
40        int m = l + (r - l) / 2;
41        mergeSort(arr, l, m);
42        mergeSort(arr, m + 1, r);
43        merge(arr, l, m, r);
44    }
45}
46
47int main() {
48    int arr[] = {12, 11, 13, 5, 6, 7};
49    int arr_size = sizeof(arr) / sizeof(arr[0]);
50    mergeSort(arr, 0, arr_size - 1);
51    for (int i = 0; i < arr_size; i++)
52        printf("%d ", arr[i]);
53    return 0;
54}
55

1#include <iostream>
using namespace std;

void heapify(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]);
        heapify(arr, n, largest);
    }
}

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

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

int main() {
    int arr[] = {12, 11, 13, 5, 6, 7};
    int n = sizeof(arr) / sizeof(arr[0]);
    heapSort(arr, n);
    for (int i = 0; i < n; i++)
        cout << arr[i] << " ";
    return 0;
}