I read this all the time from other people, but for me, Selection sort is the easiest to remember and implement. My next easiest would be Insertion sort.

Bubble sort doesn't click for me easily. I think it's because the terminating condition seems uglier than Selection sort or Insertion sort. I always have a little voice in the back of my mind, "Is this outer loop guaranteed to terminate?"

▲ archargelod 18 hours ago | parent [-]

Terminating condition in Bubble sort is "did we swap any values during this loop"? Yes -> continue, No -> list is already sorted, exit the loop.

I don't believe that insertion/selection sort is easier to grasp. Can you type it from memory, without looking it up? Here's bubble sort:

    var swapped = true
    while swapped:
      swapped = false
      for i in 0 .. list.len-2:
        if list[i] > list[i+1]:
          swap(list[i], list[i+1])
          swapped = true

▲ bxparks 5 hours ago | parent | next [-]

Different strokes for different folks I guess.

Selection sort was the first sorting algorithm that I ever created: Find the smallest element for slot #1. Find the next smallest for slot #2. And so on. I've recreated it from scratch many times. The double for-loop means that it is guaranteed to finish, and it is obviously O(N^2).

I did not learn about Bubble sort until my university class, where I thought, this is a terrible algorithm: It's not completely obvious that it will finish, and it's not obvious what the runtime complexity is. For example, if the inner loop used ">=" instead of ">", it would work for test data sets with unique elements, then hang forever with a real data set that contained duplicates.

▲ jeltz 8 hours ago | parent | prev | next [-]

Let's see.

  for i in 1 .. list.len - 1:
    j = i - 1
    while j >= 0 and list[j] > list[j + 1]:
      swap(list[j], list[j + 1])
      j = j - 1

▲ minitech 18 hours ago | parent | prev [-]

> Can you type it from memory, without looking it up?

Well, yeah, but that’s not a very useful heuristic for people who are already aware of the algorithms in question. If you ask people to come up with a way from scratch – probably without explicitly asking, in order to get better success, like by watching how they sort cards – I bet they won’t tend to come up with bubble sort. Maybe that says something about the relative intuitiveness of the approaches? Or not.

▲

3eb7988a1663 17 hours ago | parent [-]

I recall "inventing" bubble sort during one of my first CS classes when the question was posed of how to sort a list. So, not that outlandish.

	▲	avmich 14 hours ago \| parent [-]
		Agree. I remember the names of many of these algorithms, but not the logic.