What is the comparison of heap sort in C++?

What is heap sort and how does it work in C++?

Heap sort is a comparison-based sorting algorithm that uses a binary heap data structure. It works by first building a max heap from the input data, then repeatedly extracting the maximum element from the heap and rebuilding the heap until all elements are sorted.

How does heap sort compare to quicksort in terms of performance?

Heap sort has a time complexity of O(n log n) in the worst case, which is similar to quicksort. However, quicksort is often faster in practice due to better cache performance and lower constant factors, while heap sort is more stable in terms of performance across different datasets.

Are there any advantages of using heap sort over other sorting algorithms?

Yes, heap sort is not recursive, which can be an advantage in terms of memory usage. It also guarantees O(n log n) time complexity, making it reliable for large datasets.

Can you provide a simple C++ implementation of heap sort?

Sure! Here's a simple implementation:

void heapify(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(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);
    }
}

This code builds a max heap and sorts the array in place.