Function partition

CPP/sorting/randomised_quicksort.cpp:10–28

This function places all smaller to left of pivot and all greater elements to right of pivot

// to left of pivot and all greater
// elements to right of pivot
int partition(int arr[], int low, int high) {
   int pivot = arr[high];

   // Index of smaller element
   int i = (low - 1);

   for (int j = low; j <= high - 1; j++) {
       // If current element is smaller
       // than or equal to pivot
       if (arr[j] <= pivot) {

           // increment index of smaller element
           i++;
           swap(arr[i], arr[j]);
       }
   }
   swap(arr[i + 1], arr[high]);
   return (i + 1);
}

// Generates Random Pivot, swaps pivot with end element
int partition_r(int arr[], int low, int high) {