removing integers from an array - iphone

Question

I need to make an array for the co ordinates of my sprites and i wanted to remove the co-ordinate once the sprite has that co-ordinate from the array as i don't want another sprite having the same co-ordinate, i can't seem to get it to work, there are no errors and when debugging it says nsexception and quits. what am i doing wrong and where do i deallocate the arrays? when i release them in dealloc it says i need to declare them.
CGPoint cg1 = CGPointMake(33,33);
NSValue *cg1obj = [NSValue valueWithCGPoint:cg1];
CGPoint cg2 = CGPointMake(33,97);
NSValue *cg2obj = [NSValue valueWithCGPoint:cg2];
NSMutableArray *numberxy = [[NSMutableArray alloc] init]; int pointcount = 0;
[numberxy insertObject:cg1obj atIndex:pointcount++];
[numberxy insertObject:cg2obj atIndex:pointcount++];
NSMutableArray *sprites = [[NSMutableArray alloc] init]; int spritecount = 0;
[sprites insertObject:red1 atIndex:spritecount++];
[sprites insertObject:red2 atIndex:spritecount++];
for (int i=0; i<3;i++) {
int rpoint = arc4random() % 3;
int rsprite = arc4random() % 3;
CGPoint point = [[numberxy objectAtIndex:rpoint] CGPointValue];
CCSprite *sprite1 = [sprites objectAtIndex:rsprite];
sprite1.position = ccp(point.x,point.y);
if (sprite1.position.x == point.x && sprite1.position.y == point.y) {
[numberxy removeObjectAtIndex:rpoint];
[sprites removeObjectAtIndex:rsprite];
}
}

Answer 1

Your code is weird. Why is xValue defined after it is used? You may have a leak if xValue was defined previously in the same manner and now you are redefining xValue. You then check if X is in the new xValue. There is nothing in the new xValue so the if statement will evaluate to false, so nothing will be removed.
NSNumber *X = [NSNumber numberWithInt:randomNumberx];
[xValue containsObject: numberx];
xValue = [[NSMutableArray alloc]init];
if ([xValue containsObject:X]) {
[numberx removeObject:X];
}
Also what is the point of [xValue containsObject: numberx]; outside of the if statement? It doesn't have a purpose.