A static implementation of Stack & Circular Queue data structures.

StackAndQueue.cpp

// Stack is LIFO (Last In First Out)
// Circular Queue is FIFO (First In First Out)

#include <iostream>
#include <sstream>

using namespace std;

#define LENGTH_MAX 10

int stack[LENGTH_MAX];
// The top of the stack.
int top = -1;

int queue[LENGTH_MAX];
// Head of the circular queue.
int head = 0;
// Tail of the circular queue.
int tail = 0;

void stackPush(int value)
{
	if((top + 1) == LENGTH_MAX) {
		cout << "Stack is full!" << endl;
		return;
	}

	stack[++top] = value;
}

int stackPop()
{
	if(top == -1) {
		cout << "Stack is empty!" << endl;
		return 0;
	}

	return stack[top--];
}

void queueInsert(int value)
{
	if(((tail + 1) % LENGTH_MAX) == head) {
		cout << "Queue is full!" << endl;
		return;
	}

	queue[tail++] = value;
	tail %= LENGTH_MAX;
}

int queueRead()
{
	if(head == tail) {
		cout << "Queue is empty!" << endl;
		return 0;
	}

	int value = queue[head++];
	head %= LENGTH_MAX;
	return value;
}

void outputStack()
{
	for(int i = 0; i <= top; ++i) {
		cout << stack[i] << " ";
	}
}

void outputQueue()
{
	int i = head;
	while(i != tail) {
		cout << queue[i++] << " ";
		i %= LENGTH_MAX;
	}
}

int showMenu();
int getInt(char *input);

int main()
{
	while(true) {
		switch(showMenu()) {
			case 1: // Push to stack
			{
				int value = getInt("Insert a number: ");
				stackPush(value);
				break;
			}
			case 2: // Pop from stack
			{
				int value = stackPop();
				cout << "Value popped from stack: " << value << endl;
				break;
			}
			case 3: // Output entire stack
			{
				cout << "Entire stack:" << endl;
				outputStack();
				cout << endl;
				break;
			}
			case 4: // Insert into queue
			{
				int value = getInt("Insert a number: ");
				queueInsert(value);
				break;
			}
			case 5: // Read from queue
			{
				int value = queueRead();
				cout << "Value read from queue: " << value << endl;
				break;
			}
			case 6: // Output entire queue
			{
				cout << "Entire queue:" << endl;
				outputQueue();
				cout << endl;
				break;
			}
			case 7: // Exit
			{
				return 0;
			}
		}
	}

	return 0;
}

int showMenu()
{
	cout << endl;
	cout << "Stack menu:" << endl;
	cout << "1) Push to stack" << endl;
	cout << "2) Pop from stack" << endl;
	cout << "3) Output entire stack" << endl;
	cout << endl;
	cout << "Queue menu:" << endl;
	cout << "4) Insert into queue" << endl;
	cout << "5) Read from queue" << endl;
	cout << "6) Output entire queue" << endl;
	cout << endl;
	cout << "7) Exit" << endl;
	cout << endl;
	int option;
	do {
		option = getInt("Choose: ");
	} while(option<1 || option>7);
	cout << endl;
	return option;
}

int getInt(char* prompt)
{
	int output;
	string input;

	while(true) {
		cout << prompt;
		getline(cin, input);
		stringstream ss(input);

		if(ss >> output && !(ss >> input)) {
			return output;
		}
		cin.clear();
	}
}