How do you sort this array using quick sort and what complex

How do you sort this array using quick sort and what complexity is it?

81, 8, 18, 288, 300, 50, 15, 788, 10, 1, 4, 384, 898

Solution

Answer:-

QuickSort :-

QuickSort is a Divide and Conquer algorithm. It picks an element as pivot and partitions the given array around the picked pivot. There are many different versions of quickSort that pick pivot in different ways.

The key process in quickSort is partition(). Target of partitions is, given an array and an element x of array as pivot, put x at its correct position in sorted array and put all smaller elements (smaller than x) before x, and put all greater elements (greater than x) after x. All this should be done in linear time.

Program :-

#include<stdio.h>

// A utility function to swap two elements
void swap(int* a, int* b)
{
   int t = *a;
   *a = *b;
   *b = t;
}

/* This function takes last element as pivot, places
the pivot element at its correct position in sorted
   array, and places all smaller (smaller than 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]; // pivot
   int i = (low - 1); // Index of smaller element

   for (int j = low; j <= high- 1; j++)
   {
       // If current element is smaller than or
       // equal to pivot
       if (arr[j] <= pivot)
       {
           i++; // increment index of smaller element
           swap(&arr[i], &arr[j]);
       }
   }
   swap(&arr[i + 1], &arr[high]);
   return (i + 1);
}

/* The main function that implements QuickSort
arr[] --> Array to be sorted,
low --> Starting index,
high --> Ending index */
void quickSort(int arr[], int low, int high)
{
   if (low < high)
   {
       /* pi is partitioning index, arr[p] is now
       at right place */
       int pi = partition(arr, low, high);

       // Separately sort elements before
       // partition and after partition
       quickSort(arr, low, pi - 1);
       quickSort(arr, pi + 1, high);
   }
}

/* Function to print an array */
void printArray(int arr[], int size)
{
   int i;
   for (i=0; i < size; i++)
       printf(\"%d \", arr[i]);
   printf(\"\ \");
}

// Driver program to test above functions
int main()
{
  
   int arr[] = {81, 8, 18, 288, 300, 50,15,788,10,1,4,384,898};
   int n = sizeof(arr)/sizeof(arr[0]);
   quickSort(arr, 0, n-1);
   printf(\"Sorted array: \ \");
   printArray(arr, n);
   return 0;
}