
Sorting Algorithm

This is a sorting algorithm.   It may be applied to a set of data in order to sort it.    
For comparing various sorts, see compare sorts.  
For other sorting algorithms,   see sorting algorithms,   or:

O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
O(n2) sorts
Bubble sort |
Cocktail sort |
Cocktail sort with shifting bounds |
Comb sort |
Cycle sort |
Gnome sort |
Insertion sort |
Selection sort |
Strand sort
other sorts
Bead sort |
Bogo sort |
Common sorted list |
Composite structures sort |
Custom comparator sort |
Counting sort |
Disjoint sublist sort |
External sort |
Jort sort |
Lexicographical sort |
Natural sorting |
Order by pair comparisons |
Order disjoint list items |
Order two numerical lists |
Object identifier (OID) sort |
Pancake sort |
Quickselect |
Permutation sort |
Radix sort |
Ranking methods |
Remove duplicate elements |
Sleep sort |
Stooge sort |
[Sort letters of a string] |
Three variable sort |
Topological sort |
Tree sort


Task

Implement a permutation sort, which proceeds by generating the possible permutations
of the input array/list until discovering the sorted one.

Pseudocode:

while not InOrder(list) do
    nextPermutation(list)
done



import "/sort" for Sort
 
var a = [170, 45, 75, -90, -802, 24, 2, 66]
 
// recursive permutation generator
var recurse
recurse = Fn.new { |last|
    if (last <= 0) return Sort.isSorted(a)
    for (i in 0..last) {
        var t = a[i]
        a[i] = a[last]
        a[last] = t
        if (recurse.call(last - 1))  return true
        t = a[i]
        a[i] = a[last]
        a[last] = t
    }
    return false
}
 
System.print("Unsorted: %(a)")
var count = a.count
if (count > 1 && !recurse.call(count-1)) Fiber.abort("Sorted permutation not found!")
System.print("Sorted  : %(a)")