#include <stdio.h>
#include <stdbool.h>


void swap(int* intArray, int num1, int num2) {
   int temp = intArray[num1];
   intArray[num1] = intArray[num2];
   intArray[num2] = temp;
}

int partition(int* intArray, int left, int right, int pivot) {
   int leftPointer = left - 1;
   int rightPointer = right;
   while (true) {
      while (intArray[++leftPointer] < pivot) {
         //do nothing
      }
      while (rightPointer > 0 && intArray[--rightPointer] > pivot) {
         //do nothing
      }

      if (leftPointer >= rightPointer) {
         break;
      } else {
         swap(intArray, leftPointer, rightPointer);
      }
   }

   swap(intArray, leftPointer, right);
   return leftPointer;
}

void quicksort(int* array, int left, int right) {
   if (right - left <= 0) {
      return;
   } else {
      int pivot = array[right];
      int partitionPoint = partition(array, left, right, pivot);
      quicksort(array, left, partitionPoint - 1);
      quicksort(array, partitionPoint + 1, right);
   }
}