4sem_84.cpp

#include <iostream>
#include <vector>
using namespace std;

void heapify(vector<int>& arr, int n, int i) {
    int largest = i; 
    int left = 2 * i + 1; 
    int right = 2 * i + 2; 

    if (left < n && arr[left] > arr[largest]) {
        largest = left;
    }

    if (right < n && arr[right] > arr[largest]) {
        largest = right;
    }

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

        heapify(arr, n, largest);
    }
}

void heapSort(vector<int>& arr) {
    int n = arr.size();

    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);
    }
}

void printArray(const vector<int>& arr) {
    for (int i = 0; i < arr.size(); i++) {
        cout << arr[i] << " ";
    }
    cout << endl;
}

int main() {
    vector<int> arr = {12, 11, 13, 5, 6, 7};
    cout << "Original array: ";
    printArray(arr);

    heapSort(arr);

    cout << "Sorted array: ";
    printArray(arr);

    return 0;
}