One choice is to add them and remove the repeated ones: var list = new List<Car>(); list.AddRange(GetGreenCars()); list.AddRange(GetBigCars()); list.AddRange(GetSmallCars()); list = list.Distinct().ToList();
Late to the game… here’s an implementation of the MergeSort algorithm in VBA for both Arrays and Collections. I tested the performance of this implementation against the BubbleSort implementation in the accepted answer using randomly generated strings. The chart below summarizes the results, i.e. that you should not use BubbleSort to sort a VBA collection. … Read more
This comparision between Java standard collections, Trove and Colt might be helpful.
It’s just a missing case that will presumably eventually be filled in. There is no reason not to do it, and in certain cases it would be considerably faster than the immutable tree (since modifications require log(n) object creations with an immutable tree and only 1 with a mutable tree). Edit: and in fact it … Read more
Every call to the Iterator.next() moves the iterator to the next element. If you want to use the current element in more than one statement or expression, you have to store it in a local variable. Or even better, why don’t you simply use a for-each loop? for (String key : map.keySet()) { System.out.println(key + … Read more
Here it comes: abstract class TreeNode implements Iterable<TreeNode> { private Set<TreeNode> children; public TreeNode() { children = new HashSet<TreeNode>(); } public boolean addChild(TreeNode n) { return children.add(n); } public boolean removeChild(TreeNode n) { return children.remove(n); } public Iterator<TreeNode> iterator() { return children.iterator(); } } I am well trusted, but haven’t tested the implementation.
If you want to convert ListBuffer into a List, use .toList. I mention this because that particular conversion is performed in constant time. Note, though, that any further use of the ListBuffer will result in its contents being copied first. Otherwise, you can do collection.immutable.Seq(xs: _*), assuming xs is mutable, as you are unlikely to … Read more
You should not use the delete method on the Paragraphobject, but instead use the delete method of paragraphs relation, like this: post.paragraphs.delete(Paragraph.find(paragraph_id))
You didn’t provide the source of your quote, so let me quote the javadoc to you: Streams differ from collections in several ways: No storage. A stream is not a data structure that stores elements; instead, it conveys elements from a source such as a data structure, an array, a generator function, or an I/O … Read more
If Ids is a List, array or similar, L2S will translate into a contains. If Ids is a IQueryable, just turn it into a list before using it in the query. E.g.: List<int> listOfIDs = IDs.ToList(); var query = from st in dc.SomeTable where listOfIDs.Contains(st.ID) select …..