performs sorting of an integer array using counting sort algorithm in O(n) time complexity

CountingSort.java

import java.util.Scanner;

public class CountingSort 
{
	//method to get the maximum element from the array
	private int getMax(int a[],int size)
	{
		int max=a[0];
		for (int i = 1; i < size; i++) 
		{
			if(a[i]>max)
				max=a[i];
		}
		return max;
	}
	
	//method to sort the array using counting sort
	public void countingSort(int a[],int size)
	{
		int max=getMax(a, size);
		int temp[]=new int[max+1];
		int sortedArray[]=new int[size];
		int i;
		
		for(i=0;i<size;i++)
			temp[a[i]]++;
		
		for(i=1;i<=max;i++)
			temp[i]+=temp[i-1];
		
		for(i=0;i<size;i++)
		{
			sortedArray[temp[a[i]]-1]=a[i];
			temp[a[i]]--;
		}	
		
		//copying sorted array to original array
		for (i = 0; i < size; i++) 
			a[i]=sortedArray[i];
	}
	
	public void printArray(int a[],int size)
	{
		for (int i = 0; i < size; i++)
		{
			System.out.print(a[i]+" --> ");
		}
		System.out.println("END");
	}
		
	//driver function
	public static void main(String[] args) 
	{
		Scanner sc=new Scanner(System.in);
		
		int size;
		System.out.println("Enter the number of elements in the array");
		size=sc.nextInt();
		int a[]=new int[size];
		
		System.out.println("Enter the array elements:");
		for(int i=0;i<size;i++)
			a[i]=sc.nextInt();
		
		CountingSort cs=new CountingSort();
		
		System.out.println("Before Sorting:");
		cs.printArray(a, size);
		cs.countingSort(a, size);
		System.out.println("After Sorting:");
		cs.printArray(a, size);
		sc.close();
	}
}