FizzBuzz in Objective-C

fizzbuzz.m

// hey, we've all got a coding interview to crack, right?

#import <Foundation/Foundation.h>

@interface FZBZSparseArray : NSArray
- initWithCount:(NSUInteger)count placeholder:placeholder overrides:overrides;
@end

@interface FZBZWrappedArray : NSArray
- initWrappingArray:underlyingArray;
@end

@interface NSMutableDictionary (Every)
- (void)every:(NSUInteger)skip from:(NSUInteger)min upTo:(NSUInteger)max is:anObject;
@end

@interface NSNumber (FizzBuzz)
- fizzBuzzValue;
@end

@implementation NSNumber (FizzBuzz)

- fizz { return @"Fizz"; }
- buzz { return @"Buzz"; }
- fizzBuzz { return @"FizzBuzz"; }

- fizzBuzzValue
{
    static id selectors = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        id overrides = [NSMutableDictionary dictionary];
        [overrides every:3 from:3 upTo:13 is:@"fizz"];
        [overrides every:5 from:5 upTo:11 is:@"buzz"];
        overrides[@0] = @"fizzBuzz";
        id selectorMap = [[FZBZSparseArray alloc]
                          initWithCount:15
                          placeholder:@"stringValue"
                          overrides:overrides];
        selectors = [[FZBZWrappedArray alloc] initWrappingArray:selectorMap];
    });
    return [self performSelector:
            NSSelectorFromString(selectors[[self unsignedIntegerValue]])];
}

@end

@implementation NSMutableDictionary (Every)

- (void)every:(NSUInteger)skip from:(NSUInteger)min upTo:(NSUInteger)max is:anObject
{
    for (NSUInteger i = min; i < max; i += skip)
    {
        self[@(i)] = anObject;
    }
}

@end

@implementation FZBZWrappedArray
{
    id _array;
}

- initWrappingArray:underlyingArray
{
    self = [super init];
    if (self)
    {
        _array = [underlyingArray copy];
    }
    return self;
}

- (NSUInteger)count { return NSUIntegerMax; }
- objectAtIndex:(NSUInteger)index
{
    return _array[index % [_array count]];
}

@end

@implementation FZBZSparseArray
{
    id _placeholder;
    id _knownValues;
    NSUInteger _count;
}

- initWithCount:(NSUInteger)count placeholder:placeholder overrides:overrides
{
    self = [super init];
    if (self)
    {
        _placeholder = placeholder;
        _knownValues = [overrides copy];
        _count = count;
    }
    return self;
}

- objectAtIndex:(NSUInteger)index
{
    return _knownValues[@(index)] ? _knownValues[@(index)] : _placeholder;
}

- (NSUInteger)count { return _count; }

@end

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        for (NSUInteger i = 1; i < 51; i++)
        {
            printf("%s\n", [[@(i) fizzBuzzValue] UTF8String]);
        }
    }
    return 0;
}