Question

http://www.cs.pitt.edu/~kirk/cs1501/animations/Sort1.html is this applet counting right? Selection sort for 5 4 3 2 1, I see 2 swaps, but the applet is counting 4 exchanges….

Answer 1

I guess it’s a matter of definition. He is doing a swap in the end of every loop, even if he is swapping one element against itself. In his case, the swaps will be:

• Original: 5 4 3 2 1
• Swap pos 1 and 5: 1 4 3 2 5
• Swap pos 2 and 4: 1 2 3 4 5
• Swap pos 3 and 3: 1 2 3 4 5
• Swap pos 4 and 4: 1 2 3 4 5

(No swap is done for the last element since that will always be in the correct place)

A simple if statement could be used to eliminate the two last swaps.