Chapter 5, Problem 7C

Explanation of Solution

Non-recursive algorithm:

Algorithm EnumPermutation(Stack)

    Input: A stack

    Output: Number of permutations

  while !isEmpty(Stack) do

      set product <- product x pop(stack)

  endwhile

  return product

end

Explanation:

• A number of permutations can be calculated as follows,

$\begin{array}{c}\text{Number of permutations = n!}\\ \text{= n}\times \left(\text{n}-1\right)\end{array}$