priorityqueue5.cpp

来自「Think in C++ 第二版源码」· C++ 代码 · 共 44 行

//: C20:PriorityQueue5.cpp
// From Thinking in C++, 2nd Edition
// Available at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// Building your own priority queue
#include <iostream>
#include <queue>
#include <cstdlib>
#include <ctime>
using namespace std;

template<class T, class Compare>
class PQV : public vector<T> {
  Compare comp;
public:
  PQV(Compare cmp = Compare()) : comp(cmp) {
    make_heap(begin(), end(), comp);
  }
  const T& top() { return front(); }
  void push(const T& x) {
    push_back(x);
    push_heap(begin(), end(), comp);
  }
  void pop() {
    pop_heap(begin(), end(), comp);
    pop_back();
  }  
};

int main() {
  PQV<int, less<int> > pqi;
  srand(time(0));
  for(int i = 0; i < 100; i++)
    pqi.push(rand() % 25);
  copy(pqi.begin(), pqi.end(),
    ostream_iterator<int>(cout, " "));
  cout << endl;
  while(!pqi.empty()) {
    cout << pqi.top() << ' ';
    pqi.pop();
  }
} ///:~