gistfile1.m

//
//  main.m
//  project_euler_7
//
//  Created by Julius Parishy on 7/11/13.
//  Copyright (c) 2013 Fitocracy. All rights reserved.
//

#import <Foundation/Foundation.h>

BOOL isPrime(NSInteger i, NSSet *otherPrimes)
{
    for(NSNumber *num in otherPrimes)
    {
        if(i % num.integerValue == 0)
            return NO;
    }

    return YES;
}

int main(int argc, const char * argv[])
{

    @autoreleasepool {
        
        NSMutableSet *primes = [NSMutableSet setWithObject:@2];
        
        NSInteger currentInteger = 3;
        while(primes.count < 10001)
        {
            if(isPrime(currentInteger, primes))
            {
                [primes addObject:@(currentInteger)];
            }
            
            ++currentInteger;
        }
        
        NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"self" ascending:YES];
        NSArray *sortedPrimes = [primes sortedArrayUsingDescriptors:@[ sortDescriptor ]];
        
        NSLog(@"%@", sortedPrimes.lastObject);
    }
    
    return 0;
}