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@imShakil
Last active June 24, 2021 20:03
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#include <iostream>
#include <cstdlib>
using namespace std;
// define default capacity of the queue
#define SIZE 10
// Class for queue
class queue
{
int *arr; // array to store queue elements
int capacity; // maximum capacity of the queue
int front; // front points to front element in the queue (if any)
int rear; // rear points to last element in the queue
int count; // current size of the queue
public:
queue(int size = SIZE); // constructor
~queue(); // destructor
void dequeue();
void enqueue(int x);
int peek();
int size();
bool isEmpty();
bool isFull();
};
// Constructor to initialize queue
queue::queue(int size)
{
arr = new int[size];
capacity = size;
front = 0;
rear = -1;
count = 0;
}
// Destructor to free memory allocated to the queue
queue::~queue()
{
delete arr;
}
// Utility function to remove front element from the queue
void queue::dequeue()
{
// check for queue underflow
if (isEmpty())
{
cout << "UnderFlow\nProgram Terminated\n";
exit(EXIT_FAILURE);
}
cout << "Removing " << arr[front] << '\n';
front = (front + 1) % capacity;
count--;
}
// Utility function to add an item to the queue
void queue::enqueue(int item)
{
// check for queue overflow
if (isFull())
{
cout << "OverFlow\nProgram Terminated\n";
exit(EXIT_FAILURE);
}
cout << "Inserting " << item << '\n';
rear = (rear + 1) % capacity;
arr[rear] = item;
count++;
}
// Utility function to return front element in the queue
int queue::peek()
{
if (isEmpty())
{
cout << "UnderFlow\nProgram Terminated\n";
exit(EXIT_FAILURE);
}
return arr[front];
}
// Utility function to return the size of the queue
int queue::size()
{
return count;
}
// Utility function to check if the queue is empty or not
bool queue::isEmpty()
{
return (size() == 0);
}
// Utility function to check if the queue is full or not
bool queue::isFull()
{
return (size() == capacity);
}
// main function
int main()
{
// create a queue of capacity 5
queue q(5);
q.enqueue(1);
q.enqueue(2);
q.enqueue(3);
cout << "Front element is: " << q.peek() << endl;
q.dequeue();
q.enqueue(4);
cout << "Queue size is " << q.size() << endl;
q.dequeue();
q.dequeue();
q.dequeue();
if (q.isEmpty())
cout << "Queue Is Empty\n";
else
cout << "Queue Is Not Empty\n";
return 0;
}
#include<stdio.h>
struct queue{
int f, r, capacity, count;
int* q;
queue(int size)
{
f = count = 0;
r = -1;
capacity = size;
q = new int[size];
}
~queue()
{
delete q;
}
void push(int d)
{
r = (r+1)%capacity;
q[r] = d;
count++;
}
int front()
{
return q[f];
}
void pop()
{
f = (f+1)%capacity;
count--;
}
bool empty()
{
return size()==0;
}
int size()
{
return count;
}
bool overflow()
{
return (size()==capacity);
}
void exit(char e[])
{
printf("%s\n", e);
}
};
int main()
{
int n;
scanf("%d", &n); /// Initial Size of Queue
queue q(n); /// initiate queue
while(!q.overflow()) /// insert all the elements into queue.
{
int x;
scanf("%d", &x);
q.push(x);
}
while(!q.empty())
{
printf("%d\n", q.front()); q.pop(); /// display front element & pop element
}
return 0;
}
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