Notes

#include<iostream>
using namespace std;
template <typename t>
class Queue
{
int rear, front;
int size;
t *arr;
public:
Queue(int s)
{
front = rear = -1;
size = s;
arr = new t[s];
}

void createQueue(t value)
{
if ((front == 0 && rear == size - 1) ||
(rear == (front - 1) % (size - 1)))
{
cout << "queue full" << endl;
return;
}

else if (front == -1)
{
front = rear = 0;
arr[rear] = value;
}

else if (rear == size - 1 && front != 0)
{
rear = 0;
arr[rear] = value;
}

else
{
rear++;
arr[rear] = value;
}
}
t deQueue()
{
if (front == -1)
{
cout << "queue empty" << endl;
}

t data = arr[front];
arr[front] = -1;
if (front == rear)
{
front = -1;
rear = -1;
}
else if (front == size - 1)
front = 0;
else
front++;

return data;
}
void displayQueue()
{
if (front == -1)
{
cout << "queue empty" << endl;
return;
}
cout << "Elements in Queue are: " << endl;
if (rear >= front)
{
for (int i = front; i <= rear; i++)
cout<< arr[i]<<endl;
}
else
{
for (int i = front; i < size; i++)
cout << arr[i];

for (int i = 0; i <= rear; i++)
cout << arr[i];
}
}
};
#include "circular"
int main()
{
cout << "circular queue of type int" << endl;
Queue<int> q1(5);
q1.createQueue(14);
q1.createQueue(22);
q1.displayQueue();
cout << "Deleted :" << q1.deQueue() << endl;
q1.displayQueue();
cout << "circular queue of type double" << endl;
Queue<double> q2(4);
q2.createQueue(14.44);
q2.createQueue(22.23);
q2.displayQueue();
cout << "Deleted :" << q2.deQueue() << endl;
q2.displayQueue();
getchar();
return 0;
}




#include<iostream>
using namespace std;
class one
{
int a;
public:
void set(int x)
{
a = x;
}
friend class two;
};
class two
{
int b;
public:
void set_a(one& o, int v)
{
o.a = v;
cout << " value of a ="<<o.a << endl;
}
};
int main()
{
one ob1;
two ob2;
ob2.set_a(ob1, 5);
getchar();
return 0;
}



#include <iostream>
using namespace std;
template <typename T>
class Stack {
int top;

public:
T a[5];

Stack() { top = -1; }
bool push(T x)
{
if (top >= 5) {
cout << "Stack Overflow";
return false;
}
else {
a[++top] = x;
cout << x << " pushed into stackn";
return true;
}
}
T pop()
{
if (top < 0) {
cout << "Stack Underflow";
return 0;
}
else {
T x = a[top--];
return x;
}
}
int peek()
{
if (top < 0) {
cout << "Stack is Empty";
}
else {
int x = a[top];
return T;
}
}
bool isEmpty()
{
return (top < 0);
}
};
#include"stack"
int main()
{
Stack <int>s1;
Stack <double>s2;
Stack <char>s3;
s1.push(10);
s1.push(20);
s1.push(30);
cout << s1.pop() << " Popped from int stackn";
s2.push(10.33);
s2.push(20.24);
s2.push(30.33);
cout << s2.pop() << " Popped from double stackn";
s3.push('h');
s3.push('a');
s3.push('t');
cout << s3.pop() << " Popped from char stackn";
getchar();
return 0;
}