Separate array into many in a dynamic way? Obj-C - iphone

Question

I currently have this method:
-(void)seperateGuides
{
DLog("GetGuideListCount: %i", [[appDelegate getGuideList] count]);
columnOneArray = [[NSMutableArray alloc] init];
columnTwoArray = [[NSMutableArray alloc] init];
columnThreeArray = [[NSMutableArray alloc] init];
for (int i = 0; i < [[appDelegate getGuideList] count]; i = i + 3) {
[columnOneArray addObject:[[appDelegate getGuideList]objectAtIndex:i]];
}
for (int i = 1; i < [[appDelegate getGuideList] count]; i = i + 3) {
[columnTwoArray addObject:[[appDelegate getGuideList]objectAtIndex:i]];
}
for (int i = 2; i < [[appDelegate getGuideList] count]; i = i + 3) {
[columnThreeArray addObject:[[appDelegate getGuideList]objectAtIndex:i]];
}
}
And need to do this more dynamic, so I can define how many arrays I want and then get the arrays.
Different possibilities I'm considering is making it a mutli-dimensional array (although I'm not sure how to handle it in Objectvie-C), or making a method that simply loops through as many times as I define, the problem there is that I'm not quite sure how to get the different arrays.
A simple algorithm or another possible solution would be greatly appreciated.

Answer 1

The algorithm you're describing sounds equivalent to what we do when we deal a deck of cards into multiple hands, so I'd do it like this:
- (NSArray *)dealObjects:(NSArray *)objects intoArrays:(NSInteger)numArrays
{
NSMutableArray *arrays = [NSMutableArray arrayWithCapacity:numArrays];
for (a = 0; a < numArrays; a++) {
[arrays addObject:[NSMutableArray arrayWithCapacity:[objects count] / numArrays];
}
for (i = 0; i < [objects count]; i++) {
[[arrays objectAtIndex:i % numArrays] addObject:[objects objectAtIndex:i]];
}
return arrays;
}

Answer 2

You can add multiple array to another arrays as this,
-(void)seperateGuides:(int)columnCount
{
rootArray=[[NSMutableArray alloc] init];
for(int i=0;i<columnCount;i++)
{
column = [[NSMutableArray alloc] init];
for(int j=i;j<[[appDelegate getGuideList] count];j=j+3)
{
[column addObject:[[appDelegate getGuideList]objectAtIndex:j]];
[rootArray addObject:column];
[column release];
}
}
}

Answer 3

Quite simple really. Just add new NSArray objects to a root array as you iterate through your dataset.
- (void)seperateGuides {
DLog("GetGuideListCount: %i", [[AppDelegate getGuideList] count]);
NSArray *root = [[NSArray alloc] init];
int dimensions = anyIntGreaterThanZero;
for (int i = 0; i < dimensions; i += dimensions) {
NSArray *branch = [[NSArray alloc] init];
int k = 0;
for (k += i; k < [[AppDelegate getGuideList] count]; k += dimensions) {
[branch addObject:[[AppDelegate getGuideList] objectAtIndex:k]];
}
[root arrayByAddingObject:branch];
}
}

Answer 4

-(void)seperateGuides
{
NSMutableArray *parentArray = [[NSMutableArray alloc]init];
int count = [[appDelegate getGuideList] count];
int TOTAL_COLUMNS = 3;//Define number of columns here
for (int i = 0; i <count; i++)
{
int columnNo = i % TOTAL_COLUMNS;
if(parentArray.count > columnNo)
{
NSMutableArray *innerArray = [parentArray objectAtIndex:columnNo];
[innerArray addObject:[[appDelegate getGuideList]objectAtIndex:i]];
}
else
{
NSMutableArray *innerArray = [NSMutableArray arrayWithObject:[[appDelegate getGuideList]objectAtIndex:i]];
[parentArray insertObject:innerArray atIndex:columnNo];
}
}
}
Hope this helps...
Here parentArray will have NSMutableArray as its members. Each array represents the objects in a column.