Created
January 19, 2016 05:41
-
-
Save emmasteimann/b5d0eb8270c196c0008c to your computer and use it in GitHub Desktop.
Objective-C Merge Sort
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
@interface MergeSort : NSObject | |
+ (NSArray *)mergeSort:(NSArray *)mergeList; | |
@end | |
@implementation MergeSort | |
+ (NSArray *)mergeSort:(NSArray *)mergeList { | |
if([mergeList count] <= 1) { | |
return mergeList; | |
} | |
int midIndex = [mergeList count] / 2; | |
NSArray *leftArray = [self mergeSort:[mergeList subarrayWithRange:(NSRange){0, (midIndex)}]]; | |
NSArray *rightArray = [self mergeSort:[mergeList subarrayWithRange:NSMakeRange(midIndex, [mergeList count] / 2)]]; | |
return [MergeSort merge:leftArray with:rightArray]; | |
} | |
+ (NSArray *)merge:(NSArray *)left with:(NSArray *)right { | |
if ([left count] == 0) { | |
return right; | |
} else if ([right count] == 0) { | |
return left; | |
} else if (left[0] < right[0]) { | |
return [@[left[0]] arrayByAddingObjectsFromArray:[self merge:[left subarrayWithRange:(NSRange){1,[left count] - 1}] with:right]]; | |
} else { | |
return [@[right[0]] arrayByAddingObjectsFromArray:[self merge:[right subarrayWithRange:(NSRange){1,[right count] - 1}] with:left]]; | |
} | |
} | |
@end |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Golly Gee Whiz, Objective-C is verbose...