I learned that depth and height are properties of a node: The depth of a node is the number of edges from the node to the tree’s root node.A root node will have a depth of 0. The height of a node is the number of edges on the longest path from the node to … Read more
The easiest way is to invert the value of the keys and use heapq. For example, turn 1000.0 into -1000.0 and 5.0 into -5.0.
Usually a simple hash function works by taking the “component parts” of the input (characters in the case of a string), and multiplying them by the powers of some constant, and adding them together in some integer type. So for example a typical (although not especially good) hash of a string might be: (first char) … Read more
I examined the methods of System.Linq.Enumerable, discarding any that returned non-IEnumerable results. I checked the remarks of each to determine how the order of the result would differ from order of the source. Preserves Order Absolutely. You can map a source element by index to a result element AsEnumerable Cast Concat Select ToArray ToList Preserves … Read more
Here is everything about Python dicts that I was able to put together (probably more than anyone would like to know; but the answer is comprehensive). Python dictionaries are implemented as hash tables. Hash tables must allow for hash collisions i.e. even if two distinct keys have the same hash value, the table’s implementation must … Read more
Hash your objects yourself manually, and use the resulting strings as keys for a regular JavaScript dictionary. After all, you are in the best position to know what makes your objects unique. That’s what I do. Example: var key = function(obj){ // Some unique object-dependent key return obj.totallyUniqueEmployeeIdKey; // Just an example }; var dict … Read more
There are two reasons you could want to use a tree: You want to mirror the problem using a tree-like structure: For this we have boost graph library Or you want a container that has tree like access characteristics For this we have std::map (and std::multimap) std::set (and std::multiset) Basically the characteristics of these two … Read more
Try the following code. public static List<List<T>> Split<T>(IList<T> source) { return source .Select((x, i) => new { Index = i, Value = x }) .GroupBy(x => x.Index / 3) .Select(x => x.Select(v => v.Value).ToList()) .ToList(); } The idea is to first group the elements by indexes. Dividing by three has the effect of grouping them … Read more
In most cases, List<T> is more useful. LinkedList<T> will have less cost when adding/removing items in the middle of the list, whereas List<T> can only cheaply add/remove at the end of the list. LinkedList<T> is only at it’s most efficient if you are accessing sequential data (either forwards or backwards) – random access is relatively … Read more
Keep 2 stacks, let’s call them inbox and outbox. Enqueue: Push the new element onto inbox Dequeue: If outbox is empty, refill it by popping each element from inbox and pushing it onto outbox Pop and return the top element from outbox Using this method, each element will be in each stack exactly once – … Read more