priority_queue 用法

priority_queue

priority_queue 模拟

#include <vector>
namespace sjy
{//仿函数 1template <typename T>class Less{public:bool operator()(const T& x, const T& y){return x < y;}};//仿函数 2template <typename T>class Greater{public:bool operator()(const T& x, const T& y){return x > y;}};//优先级队列template <typename T, typename Container = vector<T>, typename Compare = Less<T>>class priority_queue{public://堆相关void AdjustUp(int child){Compare com;int parent = (child - 1) / 2;while (child > 0){if (com(_con[parent], _con[child])){swap(_con[parent], _con[child]);child = parent;parent = (child - 1) / 2;}else{break;}}}void AdjustDown(int parent){Compare com;int child = 2 * parent + 1;while (child < _con.size()){if (child + 1 < _con.size() && com(_con[child], _con[child + 1])){child++;}if (com(_con[parent], _con[child])){swap(_con[parent], _con[child]);parent = child;child = 2 * parent + 1;}else{break;}}}//成员函数priority_queue(){}template <typename InputIterator>priority_queue(InputIterator first, InputIterator last){while (first != last){_con.push_back(*first);++first;}for (int i = (_con.size() - 1 - 1) / 2; i >= 0; i--){AdjustDown(i);}}void push(const T& x){_con.push_back(x);AdjustUp(_con.size() - 1);}void pop(){swap(_con[0], _con[_con.size() - 1]);_con.pop_back();AdjustDown(0);}const T& top(){return _con[0];}size_t size(){return _con.size();}bool empty(){return _con.empty();}private:Container _con;};
}