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

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.

cduhn · Accepted Answer · 2012-03-26 08:13:51Z

3

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;
}

answered Mar 26, 2012 at 8:13

cduhn

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Comments

Hasintha Janka · Accepted Answer · 2012-03-26 07:29:44Z

0

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];
     }
   }
}

answered Mar 26, 2012 at 7:29

Hasintha Janka

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Comments

Alex Smith · Accepted Answer · 2012-03-26 07:48:47Z

0

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];
    }
}

answered Mar 26, 2012 at 7:48

Alex Smith

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Comments

Apurv · Accepted Answer · 2012-03-26 08:29:56Z

-(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.

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