fix dynamic array issues in sorting folder

(cherry picked from commit 01b69fcb24)

sorting/quick_sort.cpp

@@ -1,19 +1,15 @@
 /* C implementation QuickSort */
 #include <iostream>
-using namespace std;
 
-int partition(int arr[], int low, int high)
-{
-    int pivot = arr[high]; // pivot
-    int i = (low - 1);     // Index of smaller element
+int partition(int arr[], int low, int high) {
+    int pivot = arr[high];  // pivot
+    int i = (low - 1);      // Index of smaller element
 
-    for (int j = low; j < high; j++)
-    {
+    for (int j = low; j < high; j++) {
         // If current element is smaller than or
         // equal to pivot
-        if (arr[j] <= pivot)
-        {
-            i++; // increment index of smaller element
+        if (arr[j] <= pivot) {
+            i++;  // increment index of smaller element
             int temp = arr[i];
             arr[i] = arr[j];
             arr[j] = temp;
@@ -25,11 +21,8 @@ int partition(int arr[], int low, int high)
     return (i + 1);
 }
 
-void quickSort(int arr[], int low, int high)
-{
-    if (low < high)
-    {
-
+void quickSort(int arr[], int low, int high) {
+    if (low < high) {
         int p = partition(arr, low, high);
 
         quickSort(arr, low, p - 1);
@@ -37,31 +30,29 @@ void quickSort(int arr[], int low, int high)
     }
 }
 
-void show(int arr[], int size)
-{
-    for (int i = 0; i < size; i++)
-        cout << arr[i] << "\n";
+void show(int arr[], int size) {
+    for (int i = 0; i < size; i++) std::cout << arr[i] << "\n";
 }
 
 // Driver program to test above functions
-int main()
-{
+int main() {
     int size;
-    cout << "\nEnter the number of elements : ";
+    std::cout << "\nEnter the number of elements : ";
 
-    cin >> size;
+    std::cin >> size;
 
-    int arr[size];
+    int *arr = new int[size];
 
-    cout << "\nEnter the unsorted elements : ";
+    std::cout << "\nEnter the unsorted elements : ";
 
-    for (int i = 0; i < size; ++i)
-    {
-        cout << "\n";
-        cin >> arr[i];
+    for (int i = 0; i < size; ++i) {
+        std::cout << "\n";
+        std::cin >> arr[i];
     }
     quickSort(arr, 0, size);
-    cout << "Sorted array\n";
+    std::cout << "Sorted array\n";
     show(arr, size);
+
+    delete[] arr;
     return 0;
 }