priority_queue.cpp

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#include <deque>      // for deque
#include <iostream>   // for cout, endl
#include <queue>      // for priority_queue
#include <string>     // for string
#include <vector>     // for vector
 
#include <examples.h>
 
 
int main ()
{
    // Make a priority queue of int  using a vector container.
    std::priority_queue<int,
                        std::vector<int, std::allocator<int> >,
                        std::less<int> > pq;
    // Push a couple of values.
    pq.push (1);
    pq.push (2);
 
    // Pop a couple of values and examine the ends.
    std::cout << pq.top () << std::endl;
    pq.pop ();
    std::cout << pq.top () << std::endl;
    pq.pop ();
 
    // Make a priority queue of strings.
    std::priority_queue<std::string,
                        std::deque<std::string, std::allocator<std::string> >,
                        std::less<std::string> > pqs;
 
    // Push on a few strings then pop them back off.
    for (int i = 0; i < 10; i++) {
        pqs.push (std::string (i + 1, 'a'));
        std::cout << pqs.top () << std::endl;
    }
 
    for (int j = 0; j < 10; j++) {
        std::cout << pqs.top () << std::endl;
        pqs.pop ();
    }
 
    // Make a priority queue of strings using greater.
    std::priority_queue<std::string,
                        std::deque<std::string,
                                   std::allocator<std::string> >, 
                        std::greater<std::string> > pgqs;
 
    // Push on a few strings then pop them back off.
    for (int k = 0; k < 10; k++)  {
        pgqs.push (std::string (k + 1, 'a'));
        std::cout << pgqs.top () << std::endl;
    }
 
    for (int m = 0; m < 10; m++) {
        std::cout << pgqs.top () << std::endl;
        pgqs.pop ();
    }
 
    return 0;
}