quicksort.c

# include <conio.h>
# include <stdio.h>

void main(){
  int n, a[20], min, max, i;

  // Created a function to sort the array
  int sortArray(a[20], min, max);

  // For scanning the total number of elements in unsorted array
  scanf("%d\n", &n);

  // For scanning the array
  for(i=0; i<n; i++) scanf("%d ", &a[i]);

  // Function called for sorting
  a = sortArray(a, 0, n);

  //Output of the sorted Array
  for(i = 0; i < n; i++) printf("%d\t", &a[i]);
  getch();
}

int sortArray(a, min, max){
  /*
  ** As we are checking before sending to the function
  ** if(min==max) return a; <- Not Required
  */

  int p = a[min], i = min, j = max, temp;
  
  /*
  ** The loop shall run until the j does not overtakes i
  ** i.e., j < i
  */
  while(j >= i){
    if((a[i] > p) && (a[j] < p)){
      temp = a[i];
      a[i] = a[j];
      a[j] = temp;
    }
    else if(a[i] <= p) i++;
    else if(a[j] > p) j--;
  }

  /*
  ** When j overtakes i as j < i
  ** The pivot element has to swap
  */
  temp = p;
  p = a[j];
  a[j] = temp;

  /*
  ** Checking before sending to the function that it does not have only 1 element to sort
  */
  if(j-1 != 0){
    // For Sorting the Left Side of the Shifted pivot
    a = sortArray(a, 0, j-1);
  }
  if(j+1 != max){
    // For Sorting the Right Side of the Shifted pivot
    a = sortArray(a, j+1, max);
  }
  return a;
}