8. STL priority queue #

Created Sunday 16 February 2020

• The priority_queue is actually a max priority queue.
• The only difference is in the remove and insert functions, i.e < becomes > and vice-versa, i.e sifting condition.
• void pop() to remove(), push() to insert.
• p.empty() - returns true if empty.
• p.top() - returns root of the heap.
• p.size() - returns the size.
• priority_queue<int, vector, greater> for min priority queue.
• No need to include, as queue has it already.
• By default, the functor is less<int>.
• By default, priority_queue<int, vector, less>
• We will see the details afterwards.

priority_queue<int, vector<int>, greater<int>> min_pq;
priority_queue<int> max_pq;