What are the functions of priority_queue in C++?

Priority_queue in C++ is a type of container for priority queues that serves the following purposes:

1. Implement priority scheduling: a priority_queue automatically sorts and schedules elements based on their priority. When inserting elements, they are automatically placed in the appropriate position based on their priority. When accessing elements, the element with the highest priority is returned.
2. Implementing heap sort: priority_queue uses heap data structure as its underlying implementation, making it convenient to perform heap sort operations. By inserting all elements into the priority_queue and then sequentially taking them out, we can obtain a sorted sequence.
3. Quickly find the maximum (or minimum) element: priority_queue can quickly find the element with the highest (or lowest) priority. By accessing the head element of the queue, you can obtain the element with the highest priority in the queue.
4. Implementing greedy algorithms: In some greedy algorithms, it is necessary to make selections and process elements based on their priorities. The priority_queue offers convenient operations to implement these greedy algorithms.

In conclusion, priority_queue is very useful in scenarios where processing according to priority is needed and can provide efficient operations.