
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.




#import <Foundation/Foundation.h>
 
#define esign(X) (((X)>0)?1:(((X)<0)?-1:0))
 
int main()
{
  @autoreleasepool {
 
    NSMutableArray *arr =
    [NSMutableArray
      arrayWithArray: [@"this is a set of strings to sort"
                       componentsSeparatedByString: @" "]
     ];
 
    [arr sortUsingComparator: ^NSComparisonResult(id obj1, id obj2){
      NSComparisonResult l = esign((int)([obj1 length] - [obj2 length]));
      return l ? -l // reverse the ordering
               : [obj1 caseInsensitiveCompare: obj2];
     }];
 
    for( NSString *str in arr )
    {
      NSLog(@"%@", str);
    }
 
  }
  return EXIT_SUCCESS;
}