Answer
procedure arrange $( a_1, a_2, a_3, ...: $ a sequence of integers $)$
if $(a_2>a_3)$ then swap $(a_2, a_3)$
if $ (a_1 > a_2)$ then swap $(a_1, a_2)$
if $(a_2 > a_3)$ then swap $(a_2, a_3)$
procedure swap $(a_1, a_2)$
{swaps the values of two variables}
temp $:= a_1$
$a_1 := a_2$
$a_2:= $temp
Work Step by Step
This algorithm attempts to arrange the first three values of a sequence. Notice that we first define a smaller algorithm called swap to avoid having to repeat the same code three times.
Notice also that we compared $a_2$ and $a_3$ twice. This makes more sense when you consider the following sequence $10, 2, 3, ...$. In this case, $a_1$ is the largest value and it would need two steps for it to reach $a_3$. It first moves from $a_1$ to $a_2$ but then we need another statement to make sure it moves to $a_3.$
