stack updated. queue added.

Author: phyex0

src/com/company/DataStructures/Queue.java

@@ -1,14 +1,55 @@
 package com.company.DataStructures;
-
+//Todo: Add comments and explanations.
 public class Queue {
  private int[] arr;
- private int front;
- private int rear;
+ private int front=0;
+ private int rear=-1;
  private int size;
-
+ private int count=0;
 
  public Queue(int size) {
  this.size = size;
  arr = new int[this.size];
  }
+
+ private boolean isEmpty(){
+ if(count==0){
+ System.out.println("Queue is empty!");
+ return true;
+ }
+ return false;
+ }
+
+ private boolean isFull(){
+ if(count==size){
+ System.out.println("Queue is full!");
+ return true;
+ }
+ return false;
+ }
+
+ public void enqueue(int val){
+ if(!isFull()){
+ arr[++rear % size]=val;
+ count++;
+ }
+
+
+ }
+
+ public int peek(){
+ if(!isEmpty())
+ return arr[rear];
+ return -1;
+ }
+
+ public int dequeue(){
+ if(!isEmpty()){
+ count--;
+ return arr[front++ % size];
+ }
+ return -1;
+ }
+
+
 }

src/com/company/Main.java

@@ -1,22 +1,24 @@
 package com.company;
 
+import com.company.DataStructures.Queue;
 import com.company.DataStructures.Stack;
 
 public class Main {
 
  public static void main(String[] args) {
 // write your code here
- Stack myStack = new Stack(5);
+
+ Queue myQueue = new Queue(5);
 
  for(int i=0;i<5;i++){
- myStack.push(i*10);
- System.out.println(myStack.peek());
+ myQueue.enqueue(i*10);
+ System.out.println(myQueue.peek());
  }
- myStack.push(20);
+ myQueue.enqueue(20);
 
  for(int i=0;i<5;i++)
- System.out.println(myStack.pop());
- System.out.println(myStack.pop());
+ System.out.println(myQueue.dequeue());
+ System.out.println(myQueue.dequeue());
 
 
  }