Have you actually looked at the insertion sort algorithm? It doesn't allocate any additional memory. Neither does bubble sort or selection sort.
Knuth does some analysis of Bubble Sort in Volume 3 of the Art of Computer Programming, which proves bubble sort performs more comparisons and more swap operations than insertion sort. To quote the conclusion: "[A]lthough the techniques used in the calculations [to analyze the bubble sort] are instructive, the results are disappointing since they tell us that the bubble sort isn't really very good at all. Compared to straight insertion […], bubble sorting requires a more complicated program and takes about twice as long!"
6 comparisons, 1 swap with bubble and it stops. I make it 7 memory reads and 2 memory writes.
Insertion and selection sorts are going to run in half that time? I'd really like to see that! I think Knuth might be talking about a general case of any data rather than the topic being discussed here, but no, I haven't read Knuth on bubble sort so I can't be sure. I may do so now so thank you for the pointer. Arguments from authority really can be informative and useful despite their other shortcomings.
To avoid confusion, here's the bubble sort algorithm:
procedure bubbleSort( A : list of sortable items )
n = length(A)
repeat
swapped = false
for i = 1 to n-1 inclusive do
if A[i-1] > A[i] then
swap(A[i-1], A[i])
swapped = true
end if
end for
n = n - 1
until not swapped
end procedure
As you can see, after performing a swap during the first pass through the array it has to go through again (though it can skip the last element because we know the last element must contain the largest element in the array)Insertion sort will perform 7 comparisons, 1 swap, 7 memory reads and 2 writes.
Perhaps harry8 was thinking of the bubble sort implementation in the OP, which would indeed stop after one pass in these cases.
What is it with this thread and "nyer, you're wrong" responses? It's not helpful, not clever, not useful and not pleasant to read for anybody. Finding out you're wrong is great, I learn stuff.