#Task Manager Desktop App - Java //JAVA code //Anum Tahir, Nayab Javed

class node { public int data; //event details String description; String time; String date; int priority;

public
node()
{
	data = 0;
	priority = 0;
}

}

class stack { private //for priority queues (to rearrange the elements of queue) static final int size =100; int[] array = new int[size]; int top;

public
stack()
{
	top = -1;    //setting the top intially to -1
}

boolean is_full()
{
	if (top == (size - 1))
		return true;

	else
		return false;

}
boolean stack_is_empty()
{
	if (top == -1)
		return true;
	else
		return false;
}

void push(int val)			//to add an element into the stack
{
	if (is_full() == true)
	{
		System.out.println("stack overflow");
	}
	else
	{
		top++;
		array[top] = val;
	}
}

void pop()				//to remove an element from the stack
{
	if (stack_is_empty() == true)
	{
		System.out.println("stack underflow");
	}
	else
	{
		top--;
	}

}
int get_top_data()
{
	if (stack_is_empty())
		return -1;
	if (is_full())
		return 0;
	else

		return array[top];
}

}

class queues { private static final int size = 100; int[] array=new int[size]; int front; int last; stack s; node n; public queues() { front = -1; last = -1; }

boolean is_empty()
{
	if (front == -1)
		return true;
	else
		return false;
}

void insert(int v)
{
	if (is_empty())
	{
		front++;
		last++;
		array[front] = v;
	}
	else
	{
		last++;
		array[last] = v;
	}
}
void remove()
{
	if (is_empty())
	{
		System.out.println("stack underflow");
	}
	else
	{
		array[front] = 0;
		front++;
	}
}
int get_first()
{
	if (is_empty())
	{
		System.out.println("queue is empty");
		return 0;
	}
	else
	{
		return array[front];
	}
}

void priority_queue(int v)			//to set the priorties of tasks to perform
{
	
	switch (n.priority)
	{
	case '1':
		insert(v);
		break;
	case '2':

		while (n.priority != 2)
		{
			s.push(get_first());
			remove();
		}
		insert(v);
		while (!s.stack_is_empty())
		{
			insert(s.get_top_data());
		}
		break;
	case '3':
		while (n.priority != 3)
		{
			s.push(get_first());
			remove();
		}
		insert(v);
		while (!s.stack_is_empty())
		{
			insert(s.get_top_data());
		}
		break;

	}
}

}

public class Main { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub

	stack S1=new stack();			//testing member functions of stack
	System.out.println("push");
	S1.push(5);
	S1.push(4);
	S1.push(3);
	S1.push(2);
	S1.push(1);
	System.out.println("get top value");
	System.out.println(S1.get_top_data());
	System.out.println("\n\n\n");

	System.out.println("copy constructor");
	stack S2 = S1;
	S2.push(9);
	System.out.println("get top value");
	System.out.println(S1.get_top_data());
	System.out.println("\n\n\n");

	System.out.println("copy constructor");
	S1.pop();
	System.out.println("\n");

	System.out.println("get top value");
	System.out.println(S1.get_top_data());
	System.out.println("\n");
	queues Q1 = new queues();			//testing member functions of queues
	Q1.insert(1);
	Q1.insert(2);
	Q1.insert(3);
	Q1.insert(4);
	Q1.insert(5);
	System.out.println(Q1.get_first());
	System.out.println("\n");

	Q1.remove();
	Q1.remove();
	System.out.println(Q1.get_first());
	System.out.println("\n");

	queues Q2 = Q1;
	System.out.println(Q2.get_first());
	System.out.println();
	
}

}