what is a priority queue code example

Example 1: python priority queue

from queue import PriorityQueue

class PqElement(object):
    def __init__(self, value: int):
        self.val = value

    #Custom Compare Function (less than or equsal)
    def __lt__(self, other):
        """self < obj."""
        return self.val > other.val

    #Print each element function
    def __repr__(self):
        return f'PQE:{self.val}'

#Usage-
pq = PriorityQueue()
pq.put(PqElement(v))       #Add Item      - O(Log(n))
topValue = pq.get()        #Pop top item  - O(1)
topValue = pq.queue[0].val #Get top value - O(1)

Example 2: implemetation of priority queue in c++

// Implementation of priority_queue in c++

//queue with elements in decreasing order
priority_queue<int> pq;

// queue with elements in increasing order  using compare function inside declaration
priority_queue <int, vector<int>, greater<int> > pq;

//priority_queue of type pair<int, int>
#define pp pair<int, int>
priority_queue <pp, vector<pp>, greater<pp> > pq;

Example 3: priority_queue

std::priority_queue<int, std::vector<int>, std::greater<int>>