PriorityQueue

Priority Queue

A Priority Queue is a queue in which the pop() operation removes the "largest" item in the list, defined either by its natural ordering or a comparator.

• C++ priority queue
• Java PriorityQueue

Certain algoritims (particularly Dijkstra's) may require changing the priority of an item in the queue. C++'s priority_queue is simply a wrapper for make_heap, push_heap, and pop_heap (defined in #include<algorithm>). When using such algorithms, it is easiest to just use those functions directly, by modifying the priority in-place and calling make_heap. Java does not support such re-prioritizing, so you must first remove the item from the queue, change its priority, then add it again.

• C++ make heap
• C++ push heap
• C++ pop heap