Selection Sort in Action

Let’s walk through the steps of Selection Sort using the example array [4, 2, 7, 1, 3].

We begin our first pass-through:

We set things up by inspecting the value at index 0. By definition, it’s the lowest value in the array we’ve encountered so far (as it’s the only value we’ve encountered so far), so we keep track of its index in a variable:

images/optimizing_code_with_and_without_big_o/selection_sort_1.png

Step 1: We compare the 2 with the lowest value so far (which happens to be 4):

images/optimizing_code_with_and_without_big_o/selection_sort_2.png

The 2 is even less than the 4, so it becomes the lowest value so far:

Step 2: We compare the next value—the ...

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