countしてsort

sort.m

NSDictionary *dictionary = AZ_ASTCount(
    @[@"a", @"d", @"d", @"a", @"d", @"c", @"b", @"c"], ^id <NSCopying>(NSString *obj) {
        return obj;
    });
NSArray *orderedKeys = [dictionary keysSortedByValueUsingComparator:^NSComparisonResult(id obj1, id obj2) {
    return [obj1 compare:obj2];
}];
NSLog(@"dictionary = %@", orderedKeys);
/*
dictionary = (
    b,
    c,
    a,
    d
)
 */