Bug Fix heap sort [Fresh Implementation]

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 <algorithm>
-#include <cassert>
 #include <iostream>
 
 /**
- *
+ * 
  * Utility Lambda function to print the array after
  * sorting.
  *
@@ -33,32 +33,25 @@
  * @param sz size of array
  *
  */
-template <typename T>
-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 <typename T>
-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 <typename T>
-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;
 }
+/** @} */