Approach 1: Compare consecutive numbers

Work an example by hand here.

Summarizing:

• Initialize a swapflag to false.
• Start from top (i = 1) and repeatedly compare (and swap if needed) $a(i)$ with $a(i+1)$ until $i = n - 1$. (this pushes biggest number to bottom of array).
• If no swap was needed, array is in order. Exit.
• Start again from top (i = 1) and repeatedly compare (and swap if needed) $a(i)$ with $a(i+1)$ until $i = n-2$. (this pushes second biggest number to bottom-1 of array).
• If no swap was needed, array is in order. Exit.
• ...

  (continue like this, how many times?)

We need to understand ``repeated'' execution of same statements (called LOOPS).