import java.util.Random;
import java.util.Arrays;

class CountingSort {
    public static int[] sort(int[] A, int k) {
	int[] B = new int[A.length];
	int[] C = new int[k];
	// initialize counting array
	for (int i = 0; i < k; i++) {
	    C[i] = 0;
	}
	// count instances of values stored in A[j]
	for (int j = 0; j < A.length; j++) {
	    C[A[j]] += 1;
	}
	// produce cumulative totals in C so that
	// C[i] contains the number of elements <= i
	for (int i = 1; i < k; i++) {
	    C[i] += C[i-1];
	}
	// sort using position dictated by C[i]
	for (int j = A.length - 1; j >= 0; j--) {
	    B[C[A[j]] - 1] = A[j];       // put A[j] in B in position C[A[j]] - 1
	    C[A[j]] = C[A[j]] - 1;       // update count for C[A[j]]
	}

	return B;
    }

    public static void main(String[] args) {
	final int ARRSZ = 10;      // size of array
	final int NUMNUMS = 10;    // number of possible values
	Random r = new Random();
	int[] A = new int[ARRSZ];

	// populate array
	for (int j = 0; j < ARRSZ; j++) {
	    A[j] = r.nextInt(NUMNUMS);
	}

	// sort
	int[] B = sort(A, NUMNUMS);

	// print
	System.out.println(Arrays.toString(A));
	System.out.println(Arrays.toString(B));
    }
}