Question

Please Answer this question using the language of C++. I provide you with the picture of figure 18_02. Thank you.

Answer 1

As i can see that you have implemented stack with the help of deque. deque stands for double ended queue i.e. you can insert and delete from both end. you want to use stl i.e. standard template library so i'll show you how you can use deque in stl for implementing standard queue.

#ifndef QUEUE_H

#define QUEUE_H

#include<deque>

#include<iostream>

using namespace std;

template <class T>

class Queue

{

public:

//return the first element of the queue

const T& front()

{

   return queue.front();// it will return the first element's reference

}

// return the back element of the queue

const T& back()

{

   return queue.back();// it will return the back element's reference
}

// push element at the back of the queue

void push(const T& pushValue)

{

queue.push_back(pushValue);

}

// pop element from the front of the queue

void pop()

{

queue.pop_front();

}

// determine whether queue is empty

bool isEmpty() const{

return queue.empty();

}

//return size of the queue

size_t size() const{

return queue.size();

}

// to show the current queue
void show()
{
   typename deque <T>::iterator it;
   for(it=queue.begin();it!=queue.end();++it)
       cout<<'\t'<<*it;
   cout<<'\n';
}
private:

deque <T> queue;

};

#endif

int main()
{
   Queue <int> qu;
   qu.push(10);
   qu.push(20);
   qu.push(30);
   cout<<"the queue is";
   qu.show();
   cout<<"\n queue size:"<<qu.size();
   cout<<"\n queue front:"<<qu.front();
   cout<<"\n queue back:"<<qu.back();
   qu.pop();
   cout<<"\n after removal of element:"; //value 10 is removed as this is the first element inserted
   qu.show();
   return 0;
}