Objective-C tutorial

Cell.h

//
//  Cell.h
//  Cell
//
//  Created by Kirill Klenov on 09.11.13.
//  Copyright (c) 2013 Kirill Klenov. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface Cell : NSObject

@property NSMutableArray *DNA;

@property (readonly) NSArray *choices;

-(int) hammingDistance:(Cell *)c;

@end

Cell.m

//
//  Cell.m
//  Cell
//
//  Created by Kirill Klenov on 09.11.13.
//  Copyright (c) 2013 Kirill Klenov. All rights reserved.
//

#import "Cell.h"

@implementation Cell

-(id) init {
    
    self = [super init];
    
    _choices = [[NSArray alloc] initWithObjects:@"A",@"T",@"G",@"C", nil];
    
    _DNA = [[NSMutableArray alloc] initWithCapacity:100];
    
    for (int i = 0; i < 100; i++) {
        int num = arc4random() % 4;
        
        _DNA[i] = _choices[num];
        
    }
    return self;
    
}

-(int) hammingDistance:(Cell *)c {
    int distance = 0;
    for (int i = 0; i < 100; i++) {
        NSString *a = _DNA[i];
        NSString *b = [c DNA][i];
        distance = a == b ? distance : distance + 1;
    }
    return distance;
}

@end

main.m

//
//  main.m
//  Cell
//
//  Created by Kirill Klenov on 09.11.13.
//  Copyright (c) 2013 Kirill Klenov. All rights reserved.
//

#import <Foundation/Foundation.h>
#import "Cell.h"

@implementation Cell (mutator)

-(void) mutate:(int)g {
    for (int i = 0; i < g; i++) {
        int p = arc4random() % 4;
        self.DNA[p] = self.choices[p];
    }
}

@end

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

    @autoreleasepool {
        
        Cell *a, *b;
        a = [[Cell alloc] init];
        b = [[Cell alloc] init];
        
        int d = [a hammingDistance:b];
        NSLog(@"%i", d);
        
        [a mutate:50];
        [b mutate:50];
        
        d = [a hammingDistance:b];
        NSLog(@"%i", d);

        
    }
    return 0;
}