stable counting sort in java

CountingSort.java

public class CountingSort{
  public static void main(String[] args){
		int[] a = {5,6,7,1,2,4,5,6,1,0,3,4,2};
		printArray(countingSort(a, 7));
	}
	
	public static int[] countingSort(int[] a, int k){
		int[] b = new int[a.length];
		int[] c = new int[k + 1];
		for(int i = 0; i < a.length; i++)
			c[a[i]] = c[a[i]] + 1;
		for(int i = 1; i < c.length; i++)
			c[i] = c[i] + c[i-1];
		printArray(a);
		printArray(b);
		printArray(c);
		for(int i = a.length - 1; i >= 0; i--){
			b[ c[a[i]]-1 ] = a[i];
			c[a[i]] = c[a[i]] - 1;
		}
		return b;
	}
	
	public static void printArray(int[] a){
		for(int x: a){
			System.out.print(x + " ");
		}
		System.out.println("");
	}
}