13-4 with double pointer

[rocketangel]

Code: (Objective-C)

#import <Foundation/Foundation.h>
#import "Fraction.h"
#import "MathOps.h"

int main (int argc, const char * argv[]) {
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];

	int size = 5;
	
	Fraction * fractions[size]; 
	Fraction ** fracPtr = nil;  
	Fraction *addFractions( Fraction *array[], int length ); // prototype
	
	// initialization
	for (fracPtr = fractions; fracPtr < (fractions + size); fracPtr++) {
		*fracPtr = [[Fraction alloc] init];
		[*fracPtr setTo:1 over:3];
	}
	
	// add
	Fraction * result = addFractions( fractions, size );
	
	// print
	printf("Sum is %i/%i\n", [result numerator], [result denominator]);
	
	// release
	for (fracPtr = fractions; fracPtr < (fractions + size); fracPtr++)
		[*fracPtr release];
	
    [pool drain];
    return 0;
}

Fraction *addFractions( Fraction *array[], int length ) 
{
	Fraction ** fractPtr = array; 
	Fraction *sum = [[Fraction alloc] init], *temp;
	[sum setTo:0 over:1];
	
	for ( ; fractPtr < (array + length); fractPtr++ ) {
		temp = [sum add:*fractPtr];
		[sum release];
		sum = temp; 
	}
	
	return sum;
	
}