# binary priority queue

(data structure)

**Definition:**
A *priority queue* implemented with a *binary tree* having the following restrictions:

- The
*key* of a *node* is greater than keys of its *children*, i.e., it has the *heap property*. - If the right
*subtree* is not empty, the left subtree is not empty. - If there are both left and right children, the left child's key is greater than the right child's key.

**Generalization** (I am a kind of ...)

*priority queue*.

**Aggregate child** (... is a part of or used in me.)

*binary tree*, *heap property*.

**See also**
*leftist tree*, *heap*.

*Note:
The subtree restriction means that when inserting at a leaf, the left subtree is always used before the right subtree. Favoring the left subtree tends to make the tree taller and thinner. *

*
** After [GBY91, pages 223-225].*

Author: PEB

## Implementation

Gonnet and Baeza-Yates insert (C and Pascal) and delete (C and Pascal)

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Entry modified 12 February 2019.

HTML page formatted Wed Mar 13 12:42:45 2019.

Cite this as:

Paul E. Black, "binary priority queue", in
*Dictionary of Algorithms and Data Structures* [online], Paul E. Black, ed. 12 February 2019. (accessed TODAY)
Available from: https://www.nist.gov/dads/HTML/binaryPriorityQueue.html