diff --git a/sorting/heap_sort.cpp b/sorting/heap_sort.cpp index ef9f87094..405e4641d 100644 --- a/sorting/heap_sort.cpp +++ b/sorting/heap_sort.cpp @@ -1,31 +1,31 @@ /** + * \addtogroup sorting Sorting Algorithm + * @{ * \file * \brief [Heap Sort Algorithm - * (heap sort)](https://en.wikipedia.org/wiki/Heapsort) implementation + * (HEAP SORT)](https://en.wikipedia.org/wiki/Heapsort) implementation * * \author [Ayaan Khan](http://github.com/ayaankhan98) * * \details - * Heap-sort is a comparison-based sorting algorithm. - * Heap-sort can be thought of as an improved selection sort: - * like selection sort, heap sort divides its input into a sorted - * and an unsorted region, and it iteratively shrinks the unsorted - * region by extracting the largest element from it and inserting - * it into the sorted region. Unlike selection sort, - * heap sort does not waste time with a linear-time scan of the - * unsorted region; rather, heap sort maintains the unsorted region - * in a heap data structure to more quickly find the largest element + * heapsort is a comparison-based sorting algorithm. + * Heapsort can be thought of as an improved selection sort: + * like selection sort, heapsort divides its input into a sorted + * and an unsorted region, and it iteratively shrinks the unsorted + * region by extracting the largest element from it and inserting + * it into the sorted region. Unlike selection sort, + * heapsort does not waste time with a linear-time scan of the + * unsorted region; rather, heap sort maintains the unsorted region + * in a heap data structure to more quickly find the largest element * in each step. - * - * Time Complexity - \f$O(n \log(n))\f$ + * + * Time Complexity - O(nlog(n)) * */ -#include -#include #include /** - * + * * Utility Lambda function to print the array after * sorting. * @@ -33,32 +33,25 @@ * @param sz size of array * */ -template -void printArray(T *arr, int sz) { - for (int i = 0; i < sz; i++) std::cout << arr[i] << " "; +auto printArray = [] (int *arr, int sz) { + for (int i = 0 ; i < sz ; i++) + std::cout << arr[i] <<" "; std::cout << "\n"; -} +}; /** * - * \addtogroup sorting Sorting Algorithm - * @{ - * - * The heapify procedure can be thought of as building a heap from - * the bottom up by successively sifting downward to establish the - * heap property. - * - * @param arr array to be sorted - * @param n size of array - * @param i node position in Binary Tress or element position in - * Array to be compared with it's childern - * + * The heapify procedure can be thought of as building a heap from + * the bottom up by successively sifting downward to establish the + * heap property. + * + * @param arr array be to sorted + * @param */ -template -void heapify(T *arr, int n, int i) { +void(*heapify)(int *arr, int n, int i) = [] (int *arr, int n, int i) { int largest = i; - int l = 2 * i + 1; - int r = 2 * i + 2; + int l = 2*i + 1; + int r = 2*i + 2; if (l < n && arr[l] > arr[largest]) largest = l; @@ -70,54 +63,33 @@ void heapify(T *arr, int n, int i) { std::swap(arr[i], arr[largest]); heapify(arr, n, largest); } -} +}; /** - * Utilizes heapify procedure to sort + * heapSort lambda function utilizes heapify procedure to sort * the array * * @param arr array to be sorted * @param n size of array * */ -template -void heapSort(T *arr, int n) { - for (int i = n - 1; i >= 0; i--) heapify(arr, n, i); +auto heapSort = [] (int *arr, int n) { + for (int i = n-1 ; i >= 0; i--) + heapify(arr, n, i); - for (int i = n - 1; i >= 0; i--) { + for (int i = n-1 ; i >= 0; i--) { std::swap(arr[0], arr[i]); heapify(arr, i, 0); } -} - -/** - * - * @} - * Test cases to test the program - * - */ -void test() { - std::cout << "Test 1\n"; - int arr[] = {-10, 78, -1, -6, 7, 4, 94, 5, 99, 0}; - int sz = sizeof(arr) / sizeof(arr[0]); // sz - size of array - printArray(arr, sz); // displaying the array before sorting - heapSort(arr, sz); // calling heapsort to sort the array - printArray(arr, sz); // display array after sorting - assert(std::is_sorted(arr, arr + sz)); - std::cout << "Test 1 Passed\n========================\n"; - - std::cout << "Test 2\n"; - double arr2[] = {4.5, -3.6, 7.6, 0, 12.9}; - sz = sizeof(arr2) / sizeof(arr2[0]); - printArray(arr2, sz); - heapSort(arr2, sz); - printArray(arr2, sz); - assert(std::is_sorted(arr2, arr2 + sz)); - std::cout << "Test 2 passed\n"; -} +}; /** Main function */ int main() { - test(); + int arr[] = {-10, 78, -1, -6, 7, 4, 94, 5, 99, 0}; + int sz = sizeof(arr) / sizeof(arr[0]); // sz - size of array + printArray(arr, sz); // displaying the array before sorting + heapSort(arr, sz); // calling heapsort to sort the array + printArray(arr, sz); // display array after sorting return 0; } +/** @} */