Zad13

/*
19.12.2014
Problem 13 You are provided with two stacks, as well as Pop and Push functions over
them. Implement queue i.e. Enqueue and Dequeue using the available operations.
*/

#include<stdio.h>
#include<vector>
#include<iostream>

#define max 1000
using namespace std;

class Stack {

private:
    int size = 0;
    vector<int> items;
public:

    Stack(){
        items = vector<int>(1);
    }

    bool IsEmpty(){
        return size == 0;
    }
    bool IsFull(){
        return false;
        //return size == max; // ?
    }
    int Pop(){
        int popItem = items[size - 1];
        size--;
        if ((size > 0) && (size == items.size() / 4)){
            items.resize(items.size() / 2);
        }
        return popItem;
    }
    void Push(int item){
        size++;
        items[size - 1] = item;
        if (size == items.size()){
            items.resize(items.size() * 2);
        }
    }
    int Top(){
        return items[size - 1];
    }


};

class Queue{
private:
    Stack s1;
    Stack s2;
public:
    Queue(){
        s1 = Stack();
        s2 = Stack();
    }
    void Enqueue(int item){
        s1.Push(item);

    }
    int Dequeue(){
        int retVal;
        if (s2.IsEmpty()){
            while (!s1.IsEmpty()){
                int item = s1.Pop();
                s2.Push(item);
            }
        }
        retVal = s2.Pop();
        return retVal;
    }
    bool IsEmpty(){
        return s1.IsEmpty()&&s2.IsEmpty();
    }

};

int main(){
    Queue q;
    for (int i = 0; i < 10; i++){
        q.Enqueue(i);
    }

    while (!q.IsEmpty()){
        cout << q.Dequeue() << " ";
    }






}