HackerRank: Pangram

gistfile1.txt

//
//  main.m
//  Pangrams
//
//  Created by Nathan Arnold on 10/31/15.
//  Copyright © 2015 Nathan Arnold. All rights reserved.
//

#import <Foundation/Foundation.h>


int main(int argc, const char * argv[]) {
    @autoreleasepool {
        // insert code here...

        NSSet *lowerCaseChars = [NSSet setWithObjects:@"a",@"b",@"c",@"d",@"e",@"f",@"g",@"h",@"i",@"j",@"k",@"l",@"m",@"n",@"o",@"p",@"q",@"r",@"s",@"t",@"u",@"v",@"w",@"x",@"y",@"z",nil];
        
        NSMutableSet *lettersInString = [NSMutableSet setWithCapacity:26];
        
        NSMutableCharacterSet *alphaCharSet = [[NSMutableCharacterSet alloc]init];
        
        [alphaCharSet formUnionWithCharacterSet:[NSCharacterSet lowercaseLetterCharacterSet]];
        [alphaCharSet formUnionWithCharacterSet:[NSCharacterSet uppercaseLetterCharacterSet]];
        
        char c;
        
        while (scanf(" %c",&c)!=EOF) {
            
            if ([alphaCharSet characterIsMember:c]){
                NSString *string =  [NSString stringWithFormat:@"%c" , c];
                [lettersInString addObject:[string lowercaseString]];
            }
        }
        
        if ([lowerCaseChars isEqualToSet:lettersInString]){
            printf("pangram");
        } else {
           printf("not pangram");
        }

    }
    
    return 0;
}

Uses NSSets to check if a string is a pangram.