C++ (Cpp) Priority_queue::empty Examples

Programming Language: C++ (Cpp)

Class/Type: Priority_queue

Method/Function: empty

Examples at hotexamples.com: 4

Priority_queue is a container adapter that provides constant time lookup of the largest or smallest element. It is part of the C++ Standard Template Library (STL).

The empty() function in priority_queue class returns true if the priority queue is empty, and false otherwise.

Example:

#include  
#include  
using namespace std; 

int main() 
{ 
    priority_queue pq; 
    pq.push(10); 
    pq.push(20); 
    pq.push(30); 

    if(pq.empty()) 
        cout << "Priority queue is empty.\n"; 
    else
        cout << "Priority queue is not empty.\n"; 

    return 0; 
}

Output:

Priority queue is not empty.

In this example, we create a priority queue and push three elements into it. We then use the empty() function to check if the priority queue is empty. Since it is not empty, we print "Priority queue is not empty". Package library: STL (Standard Template Library)

C++ (Cpp) Priority_queue::empty - 4 examples found. These are the top rated real world C++ (Cpp) examples of Priority_queue::empty extracted from open source projects. You can rate examples to help us improve the quality of examples.

Frequently Used Methods

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empty(4)

pop(4)

push(4)

top(4)

size(2)

Frequently Used Methods

empty (4)

pop (4)

push (4)

top (4)

size (2)

Example #1

Show file

File: priority_queue.hpp Project: Mr-Anderson/james_mst_hw

Priority_queue<generic>::Priority_queue(Priority_queue & original)
{
	m_size = 0 ;
	m_root = NULL;
	m_push = NULL;
	m_pop = NULL;
	
	//create temp
	Priority_queue<generic> temp;
	
	//copy to temp
	while (!original.empty())
	{
		temp.push(original.top()) ;
		original.pop();
	}
	
	//copy temp to new and old
	while (!temp.empty())
	{
		original.push(temp.top()) ;
		push(temp.top()) ;
		temp.pop();
	}
}

Example #2

Show file

File: Priority_queue_test.cpp Project: akamel001/Data-Structures

int main()
{
   Priority_queue<int> pq;

   assert(pq.size() == 0);
   assert(pq.empty());

   pq.push(10);
   assert(pq.top() == 10);

   pq.push(20);
   assert(pq.top() == 20);

   pq.push(30);
   assert(pq.top() == 30);

   pq.push(40);
   assert(pq.top() == 40);

   pq.push(50);
   assert(pq.top() == 50);

   pq.push(5);
   assert(pq.top() == 50);

   pq.pop();
   assert(pq.top() == 40);

   pq.pop();
   assert(pq.top() == 30);

   pq.pop();
   assert(pq.top() == 20);

   pq.pop();
   assert(pq.top() == 10);

   pq.pop();
   assert(pq.top() == 5);

   pq.pop();
   assert(pq.size() == 0);

   Priority_queue<int> pq2;
   pq2.push(30);
   pq2.push(11);
   pq2.push(7);
   pq2.pop();
   assert(pq2.top() == 11);
   pq2.pop();
   assert(pq2.top() == 7);
   pq2.pop();
   assert(pq2.empty());

   cout << "All tests passed." << endl;
}

Example #3

Show file

File: priority_queue.hpp Project: Mr-Anderson/james_mst_hw

Priority_queue<generic> & Priority_queue<generic>:: operator= ( Priority_queue & original)
{
	clear();
	
	//create temp
	Priority_queue<generic> temp;
	
	//copy to temp
	while (!original.empty())
	{
		temp.push(original.top()) ;
		original.pop();
	}
	
	//copy temp to new and old
	while (!temp.empty())
	{
		original.push(temp.top()) ;
		push(temp.top()) ;
		temp.pop();
	}
	
	return *this ;
}

Example #4

Show file

File: Priority_queue_1t.cpp Project: alan23273850/Cpp_STL_Implementation

int main()
{
    const int testcases = 1000;
    Priority_queue<Int> mypq;
    priority_queue<Int> stdpq;
    int myoutput, stdoutput;

    srand( time(NULL) );

    for(int i=0; i<testcases; i++)
    {
        myoutput = -1;
        stdoutput = -1;
        int cmd = rand()%5;
        Int temp( rand()%testcases );

//        if( i<testcases/2 )
//            cmd = 3;
//        else if( i%2==0 )
//            cmd = 2;
//        else
//            cmd = 4;

        switch(cmd)
        {
            case 0:
                myoutput = mypq.empty();
                stdoutput = stdpq.empty();
                break;
            case 1:
                myoutput = mypq.size();
                stdoutput = stdpq.size();
                break;
            case 2:
                if( stdpq.size()>0 )
                {
                    myoutput = mypq.top().value();
                    stdoutput = trans(stdpq.top());
                }
                break;
            case 3:
                mypq.push(temp);
                stdpq.push(temp);
                break;
            default:
                if( stdpq.size()>0 )
                {
                    mypq.pop();
                    stdpq.pop();
                }
                break;
        }
        printf("(%d,%d) with operation %d\n",myoutput,stdoutput,cmd);
        if( myoutput!=stdoutput )
        {
            printf("fail\n");
            return 0;
        }
    }
    printf("success\n");
    return 0;
}