Java Queue Example
Chapter:
Miscellaneous
Last Updated:
28-05-2016 13:02:02 UTC
Program:
/* ............... START ............... */
public class JavaQueueExample {
int Q[]; // Array to implement Queue
int size; // Maximum size of the Queue
int front; // Index of front element
int rear; // Index of rear element
JavaQueueExample(int cap) // Parameterised Constructor
{
size = cap;
Q = new int[size];
front = 0;
rear = 0;
}
void insert(int v) // Function to insert element in Queue
{
if (rear == size) // Condition for Overflow
{
System.out.println("OVERFLOW");
} else {
Q[rear] = v; // Storing value in Queue
rear = rear + 1;
}
}
int delete() // Function to delete element from Queue
{
if (front == 0 && rear == 0) // Condition for Underflow
{
System.out.println("UNDERFLOW");
return -999;
} else {
int val = Q[front]; // Storing the element which will be removed
front = front + 1;
if (front == rear) // Condition for emptying the Queue
{
front = 0;
rear = 0;
}
return val;
}
}
void display() // Function for printing elements in the queue
{
if (front == 0 && rear == 0) {
System.out.println("The Queue is empty");
} else {
System.out.println("The elements in the queue are : ");
for (int i = front; i < rear; i++) {
System.out.println(Q[i]);
}
}
}
}
/* ............... END ............... */
Notes:
-
Queue is a linear data structure which enables the user to add elements from the rear end and remove elements from the front end only.
- Queue uses the concept of FIFO (First In First Out).
Tags
Java Queue Example, Java