
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

Sort an array (or list) of strings in order of descending length, and in ascending lexicographic order for strings of equal length.

Use a sorting facility provided by the language/library, combined with your own callback comparison function.


Note:   Lexicographic order is case-insensitive.




' version 23-10-2016
' compile with: fbc -s console
 
#Include Once "crt/stdlib.bi" ' for qsort
 
Function mycmp Cdecl (s1 As Any Pointer, s2 As Any Pointer) As Long
 
    ' -1 no swap first element before second element
    '  0 no swap needed, don't care
    '  1 swap first element after second element
 
    Dim As String str1 = *Cast(String Ptr, s1)
    Dim As String str2 = *Cast(String Ptr, s2)
 
    Dim As Long l1 = Len(str1), l2 = Len(str2)
    If (l1 > l2) Then Return -1 ' descending
    If (l1 < l2) Then Return  1 '
 
    ' there equal length, sort ascending
    If UCase(str1) = UCase(str2) Then
        If str1 > str2 Then Return 1
    Else
        If UCase(str1) > UCase(str2) Then Return 1
    End If
 
    Return 0
 
End Function
 
' ------=< MAIN >=------
 
Dim As String words(0 To ...) = {"Here", "are", "some", "sample", _
                                 "strings", "to", "be", "sorted" }
 
Dim As ULong array_size = UBound(words) - LBound(words) + 1
 
qsort(@words(0), array_size, SizeOf(String), @mycmp)
 
For i As Integer = 0 To UBound(words)
    Print words(i)
Next
Print
 
' empty keyboard buffer
While InKey <> "" : Wend
Print : Print "hit any key to end program"
Sleep
End