C++ - Priority Queue empty() Function
The C++ priority_queue::empty function is used to check whether the priority_queue is empty or not. It returns true if the size of the priority_queue is zero, else returns false.
Syntax
bool empty() const;
bool empty() const;
Parameters
No parameter is required.
Return Value
true if the size of the priority_queue is zero, else returns false.
Time Complexity
Constant i.e, Θ(1).
Example:
In the below example, the priority_queue::empty function is used to check whether the priority_queue is empty or not.
#include <iostream> #include <queue> using namespace std; int main (){ priority_queue<int> p_queue; cout<<"Is the Priority Queue empty?: "<<p_queue.empty()<<"\n\n"; cout<<"Add three elements in the Priority Queue.\n"; p_queue.push(10); p_queue.push(20); p_queue.push(30); cout<<"Now, Is the Priority Queue empty?: "<<p_queue.empty()<<"\n"; return 0; }
The output of the above code will be:
Is the Priority Queue empty?: 1 Add three elements in the Priority Queue. Now, Is the Priority Queue empty?: 0
❮ C++ - Priority Queue