c11p642b.txt

Data Abstraction & Problem Solving with C++源码

w#include <iostream>
#include <queue>
#include <vector>
#include <cstdlib>
#include <ctime>

using namespace std;

int main() 
{
  //declare a priority queue
  priority_queue<int, vector<int> > pq;
  
  // declare a vector
  vector<int> vheap;

  // declare a vector iterator
  vector<int>::iterator iter;

  // seed the random number generator
  srand(time(0));

  // fill the priority queue and vector with the random numbers
  // push each number of the vector onto a heap
  // using the greater predicate
  for (int i=0; i < 25; i++) 
  {
     int j = rand() % 25;  
     pq.push(j);
     vheap.push_back(j);
     push_heap(vheap.begin(), vheap.end(), greater<int>() );
  }  // end for

  // show the generated numbers in their original order by
  // iterating through the vector
  cout << "Original numbers: " << endl;
  for (iter = vheap.begin(); iter != vheap.end(); iter++) 
    cout << *iter << " "; 

  // display the priority queue by popping the top off
  cout << endl << "Priority queue: " << endl;
  while (!pq.empty()) 
  {
    cout << pq.top() << " ";
    pq.pop();
  }  // end while

  // display the vector as a heap by popping the top off
  cout << endl << "Heap: " << endl;
  while (!vheap.empty())
  {
    cout << vheap[0] << " ";
    pop_heap(vheap.begin(), vheap.end(), greater<int>());
    vheap.pop_back();
  }  // end while

  cout << endl;

  return 0;
}  // end main