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This module provides a BinaryHeap (aka priority queue) adaptor that makes a binary heap out of any user-provided random-access range.
This module is a submodule of std.container.
Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at boost.org/LICENSE_1_0.txt).
Steven Schveighoffer, Andrei Alexandrescu
- Implements a binary heap container on top of a given random-access range type (usually T) or a random-access container type (usually Array!T). The documentation of BinaryHeap will refer to the underlying range or container as the store of the heap.The binary heap induces structure over the underlying store such that accessing the largest element (by using the front property) is a Ο(1) operation and extracting it (by using the removeFront() method) is done fast in Ο(log n) time. If less is the less-than operator, which is the default option, then BinaryHeap defines a so-called max-heap that optimizes extraction of the largest elements. To define a min-heap, instantiate BinaryHeap with "a > b" as its predicate. Simply extracting elements from a BinaryHeap container is tantamount to lazily fetching elements of Store in descending order. Extracting elements from the BinaryHeap to completion leaves the underlying store sorted in ascending order but, again, yields elements in descending order. If Store is a range, the BinaryHeap cannot grow beyond the size of that range. If Store is a container that supports insertBack, the BinaryHeap may grow by adding elements to the container.Examples:Example from "Introduction to Algorithms" Cormen et al, p 146
import std.algorithm : equal; int a = [ 4, 1, 3, 2, 16, 9, 10, 14, 8, 7 ]; auto h = heapify(a); // largest element assert(h.front == 16); // a has the heap property assert(equal(a, [ 16, 14, 10, 8, 7, 9, 3, 2, 4, 1 ]));Examples:
- Converts the store s into a heap. If initialSize is specified, only the first initialSize elements in s are transformed into a heap, after which the heap can grow up to r.length (if Store is a range) or indefinitely (if Store is a container with insertBack). Performs Ο(min(r.length, initialSize)) evaluations of less.
- Takes ownership of a store. After this, manipulating s may make the heap work incorrectly.
- Takes ownership of a store assuming it already was organized as a heap.
- Clears the heap. Returns the portion of the store from 0 up to length, which satisfies the heap property.
- Returns true if the heap is empty, false otherwise.
- Returns the length of the heap.
- Returns the capacity of the heap, which is the length of the underlying store (if the store is a range) or the capacity of the underlying store (if the store is a container).
- Returns a copy of the front of the heap, which is the largest element according to less.
- Clears the heap by detaching it from the underlying store.
- Inserts value into the store. If the underlying store is a range and length == capacity, throws an exception.
- Removes the largest element from the heap.
- Removes the largest element from the heap and returns a copy of it. The element still resides in the heap's store. For performance reasons you may want to use removeFront with heaps of objects that are expensive to copy.
- Replaces the largest element in the store with value.
- If the heap has room to grow, inserts value into the store and returns true. Otherwise, if less(value, front), calls replaceFront(value) and returns again true. Otherwise, leaves the heap unaffected and returns false. This method is useful in scenarios where the smallest k elements of a set of candidates must be collected.
- Convenience function that returns a BinaryHeap!Store object initialized with s and initialSize.
Red-black tree code copyright (C) 2008- by Steven Schveighoffer. Other code copyright 2010- Andrei Alexandrescu. All rights reserved by the respective holders. | Page generated by Ddoc on (no date time)