COUNTING-SORT(A, B, k)
1 let C[0,…,k] be a new array
2 for i = 0 to k
3 C[i] = 0
4 for j = 1 to A.length
5 C[A[j]] = C[A[j]] + 1
6 // C[i] now contains the number of elements equal to i .
7 for i =1 to k
8 C[i] = C[i] + C[i-1]
9 // C[i] now contains the number of elements less than or equal to i .
10 for j = A.length downto 1
11 B[C[A[j]]] = A[j]
12 C[A[j]] = C[A[j]] – 1
illustrate the operation of COUNTING-SORT on the array $A=\langle 6,0,2,0,1,3,4,6,1,3,2 \rangle $