LAST3.cpp.txt

#include <iostream>
using namespace std;
struct Node 
{
	int data; 
	Node* next;
};
struct Queue 
{
	int size;
	Node* first; 
	Node* last; 
};
int size(Queue* Q)
{
	return Q->size;
}
void add(Queue* Q)
{
	int value;
	cin >> value;
	Q->last->next = new Node;
	Q->last = Q->last->next;
	Q->last->data = value;
	Q->last->next = NULL;
	Q->size++;
}
void creation(Queue* Q)
{
	Q->first = new Node;
	Q->first->next = NULL;
	Q->last = Q->first;
	Q->size = 0;
}
bool full(Queue* Q)
{
	if (Q->first == Q->last) return true;
	else return false;
}
int top(Queue* Q)
{
	return Q->first->next->data;
}
void del(Queue* Q)
{
	Q->first = Q->first->next;
	Q->size--;
}
int main()
{
	setlocale(LC_ALL, "0");
	Queue Q;
	creation(&Q);
	char number;
	while (number != '0')
	{
		cout << "1 - add element" << endl;
		cout << "2 - erase element" << endl;
		cout << "3 - out last element" << endl;
		cout << "4 - find out the element" << endl;
	 cin >> number;
		switch (number)
		{
		case '1': add(&Q);
			break;
		case '2':
			if (full(&Q)) cout << endl << "empty";
			else del(&Q);
			break;

		case '3':
			if (full(&Q)) cout << endl << "empty";
			else 
			{ 
				cout << top(&Q) << endl; 
			}
			break;
		case '4':
			if (full(&Q)) cout << endl << "empty";
			else cout << size(&Q) << endl;
			break;
			
		case '0': break;
		default: cout << endl << "error";
			break;
		}
	} 
	return 0;
}