#import <Foundation/Foundation.h>


@interface Limb : NSObject
@end // Limb

@implementation Limb

- (NSString *) description
{
    return (@"A limb.");
} // description

@end // Limb



@interface Arm : Limb
@end // Arm

@implementation Arm

- (NSString *) description
{
    return (@"An arm.");
} // description

@end // Arm


@interface Brain : NSObject
@end // Brain

@implementation Brain

- (NSString *) description
{
    return (@"A brain.!");
} // description

@end // Brain



@interface MadScientist : Brain
@end // MadScientist

@implementation MadScientist

- (NSString *) description
{
    return (@"A Mad Scientist's Brain");
} // description

@end 


@interface TheMonster : NSObject
{
    Limb *limbs[4];
    Brain *brain;
}

- (void) setBrain: (Brain *) newBrain;

- (Brain *) brain;


- (void) setLimb: (Limb *) limb
         atIndex: (int) index;

- (Limb *) limbAtIndex: (int) index;

- (void) print;

@end // TheMonster


@implementation TheMonster

- (id) init
{
    if (self = [super init]) {
        brain = [Brain new];
		
        limbs[0] = [Limb new];
        limbs[1] = [Limb new];
        limbs[2] = [Limb new];
        limbs[3] = [Limb new];
    }
	
    return (self);
	
} // init


- (Brain *) brain
{
    return (brain);
} // brain


- (void) setBrain: (Brain *) newBrain
{
    brain = newBrain;
} // setBrain


- (void) setLimb: (Limb *) limb
         atIndex: (int) index
{
    if (index < 0) {
        NSLog (@"Can't attach a negative limb!",
               index);
        exit (1);
    }
	if (index > 3) {
		NSLog (@"Can't attach more than four limbs!",
		   index);
	exit (1);
	}
	
    limbs[index] = limb;
	
} // setLimb:atIndex:


- (Limb *) limbAtIndex: (int) index
{
    if (index < 0 ) {
        NSLog (@"Can't request a negative limb!",
               index);
        exit (1);
    }
	
	if (index > 3) {
        NSLog (@"bad index (%d) in limbAtIndex:",
               index);
        exit (1);
    }
	
    return (limbs[index]);
	
} // limbAtIndex:



- (void) print
{
    NSLog (@"Our Newly Created Monster is composed of:");
	
	NSLog (@"%@", brain);
	
    NSLog (@"%@", limbs[0]);
    NSLog (@"%@", limbs[1]);
    NSLog (@"%@", limbs[2]);
    NSLog (@"%@", limbs[3]);
	
} // print

@end // TheMonster



int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
	
	TheMonster *theMonster = [TheMonster new];
	
	int i;
	for (i = 0; i < 2; i++) {
		Limb *limb = [Arm new];
		
		[theMonster setLimb: limb
					atIndex: i];
	}
	
	for (i = 2; i < 4; i++) {
		Limb *limb = [Limb new];
		
		[theMonster setLimb: limb
					atIndex: i];
	}
	
	Brain *brain = [MadScientist new];
	[theMonster setBrain: brain];
	
	[theMonster print];
	
	return (0);
	
    [pool drain];
    return 0;
}