Stable Sort

Two elements having the same value appear in the same order in the sorted sequence as they did in the input sequence.

Counting Sort is a Stable Sort.

Array A:

5 (1)

7

3 (1)

5 (2)

2

1

4

3 (2)

Array B:

1

2

3 (1)

3 (2)

4

5 (1)

5 (2)

7

If we change line from

for j = length(A) downto 1

to

for j = 1 to length(A)

Would the algorithm still sort? Yes

Would the algorithm still be a stable sort? No