力扣面试题59

力扣面试题59 - II. 队列的最大值

class MaxQueue {
	queue<int> m_Que;
	deque<int> m_Deq;
public:
	MaxQueue()
	{

	}
	
	int max_value() 
	{
		if (m_Deq.empty())
		{
			return -1;
		}
		return m_Deq.front();
	}
	
	void push_back(int value) 
	{
		while (!m_Deq.empty() && m_Deq.back() < value)
			m_Deq.pop_back();
		m_Deq.push_back(value);
		m_Que.push(value);
	}
	
	int pop_front()
	{
		if (m_Que.empty())
		{
			return -1;
		}
		int value = m_Que.front();
		m_Que.pop();
		if (m_Deq.front() == value)
		{
			m_Deq.pop_front();
		}
		return value;
	}

};

/**

 * Your MaxQueue object will be instantiated and called as such:
 * MaxQueue* obj = new MaxQueue();
 * int param_1 = obj->max_value();
 * obj->push_back(value);
 * int param_3 = obj->pop_front();
**/