Quick Sort in C [Program & Algorithm]

In this instructional exercise, you will find out about algorithm and program for snappy sort in C.

The speedy sort is the quickest interior sorting algorithm with the time multifaceted nature O (n log n).

The essential algorithm to sort an exhibit a[ ] of n components can be portrayed recursively as pursues:

Quick Sort Algorithm

On the off chance that n < = 1, at that point return.

Pick any component V in a[]. This is known as the pivot.

Revise components of the cluster by moving all components xi > V right of V and all components x­i < = V left of V.

In the event that the spot of the V after the pre-game plan is j, all components with esteem not as much as V,

show up in a[0], a[1] . . . . a[j – 1] and each one of those with esteem more prominent than V show up in a[j + 1] . . . . a[n – 1].

Apply fast sort recursively to a[0] . . . . a[j – 1] and to a[j + 1] . . . . a[n – 1].

Quick Sort Animation

Visualization of the quicksort algorithm. The horizontal lines are pivot values.

Program

#include <stdio.h>
 
void quick_sort(int[],int,int);
int partition(int[],int,int);
 
int main()
{
	int a[50],n,i;
	printf("How many elements?");
	scanf("%d",&n);
	printf("\nEnter array elements:");
	
	for(i=0;i<n;i++)
		scanf("%d",&a[i]);
		
	quick_sort(a,0,n-1);
	printf("\nArray after sorting:");
	
	for(i=0;i<n;i++)
		printf("%d ",a[i]);
	
	return 0;		
}
 
void quick_sort(int a[],int l,int u)
{
	int j;
	if(l<u)
	{
		j=partition(a,l,u);
		quick_sort(a,l,j-1);
		quick_sort(a,j+1,u);
	}
}
 
int partition(int a[],int l,int u)
{
	int v,i,j,temp;
	v=a[l];
	i=l;
	j=u+1;
	
	do
	{
		do
			i++;
			
		while(a[i]<v&&i<=u);
		
		do
			j--;
		while(v<a[j]);
		
		if(i<j)
		{
			temp=a[i];
			a[i]=a[j];
			a[j]=temp;
		}
	}while(i<j);
	
	a[l]=a[j];
	a[j]=v;
	
	return(j);
}

In the event that you discovered anything mistaken or have any questions with respect to above quick sort in C instructional exercise at that point remark beneath.