面试金典--3.5

http://www.cnblogs.com/wanghui9072229/archive/2011/11/22/2259391.html

老题目了，4月份面腾讯实习的时候问了这道题，都不用写代码的。

#include <iostream>
#include <queue>
#include <climits>
#include <algorithm>
#include <memory.h>
#include <stdio.h>
#include <ostream>
#include <vector>
#include <list>
#include <cmath>
#include <string>
#include <stdexcept>
#include <stack>
using namespace std;

class MyQueue
{
    stack<int> stackpush;
    stack<int> stackpop;
public:
    MyQueue()
    {
        
    }
    ~MyQueue()
    {
        
    }
    void enqueue(const int &elem)
    {
        stackpush(elem);
    }
    int dequeue()
    {
        if(stackpop.size() == 0)
        {
            if(stackpush.size() == 0)
                throw std::out_of_range("queue is empty");
            else
            {
                while(!stackpush.empty())
                {
                    stackpop.push(stackpush.top());
                    stackpush.pop();                    
                }
                int val = stackpop.top();
                stackpop.pop();
                return val;
            }
        }
        else
        {
            int val = stackpop.top();
                stackpop.pop();
                return val;
        }
    }
};

int main()
{

    return 0;
}