Quick Sort in C language

Quick Sort

This is a one kind of sorting technique. The complexity of this sorting technique is,
Worst-case performance : O(n^2)
Best-case performance : O(n log n)
Average-case performance : O(n log n)
For more details click here

Code

/******Quick Sort*****/
#include<stdio.h>
#include<malloc.h>
#include<stdlib.h>
//Function definition
int* quick_sort(int *arr,int low,int high){
 int pivot,i,temp,j;
 if(low<high) {
  pivot=arr[low];
  i=low;
  j=high;
 }
 else
  return arr;
 while(i<j){
  while((arr[i]<=pivot)&&(i<high))
   i++;
  while((arr[j]>=pivot)&&(j>low))
   j--;
  if(i<j){
   temp=arr[i];
   arr[i]=arr[j];
   arr[j]=temp;
  }
 }
 temp=arr[low];
 arr[low]=arr[j];
 arr[j]=temp;
 quick_sort(arr,low,j-1);
 quick_sort(arr,j+1,high); 
}
//Main function started
int main(){
 int *arr,n,i;
 while(1){
  //Taking the number of element
  printf("\nEnter the number of element you want to store:");
  scanf("%d",&n);
  if(n<=0){
   printf("\nAn array size must be a positive integer.");
   continue;
  }
  else
   break;
 }
 //Creating the array dynamically
 arr=(int*)malloc(n*sizeof(int));
 if(!arr) {
  printf("\nNot enough memory.");
  exit(0);
 }
 printf("\nEnter the element(s) in the array:");
 for(i=0;i<n;i++){
  printf("\nElement[%d]:",i+1);
  scanf("%d",&arr[i]);
 }
 printf("\nThe element(s) before sorting:");
 for(i=0;i<n;i++)
  printf(" %d",arr[i]);
 printf("\nThe element(s) after sorting:");
 arr=quick_sort(arr,0,n-1);
 for(i=0;i<n;i++)
  printf(" %d",arr[i]);
 return 0;
}

Output

Enter the number of element you want to store:7

Enter the element(s) in the array:
Element[1]:5

Element[2]:6

Element[3]:2

Element[4]:88

Element[5]:554

Element[6]:11

Element[7]:36

The element(s) before sorting: 5 6 2 88 554 11 36
The element(s) after sorting: 2 5 6 11 36 88 554