118 lines
3.0 KiB
Java
118 lines
3.0 KiB
Java
package DataStructures.Queues;
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//This program implements the concept of CircularQueue in Java
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//Link to the concept: (https://en.wikipedia.org/wiki/Circular_buffer)
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public class CircularQueue {
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public static void main(String[] args) {
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circularQueue cq= new circularQueue(5);
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System.out.println(cq.isEmpty());
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System.out.println(cq.isFull());
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cq.enQueue(1);
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cq.enQueue(2);
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cq.enQueue(3);
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cq.enQueue(4);
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cq.enQueue(5);
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System.out.println(cq.deQueue());
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System.out.println(cq.deQueue());
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System.out.println(cq.deQueue());
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System.out.println(cq.deQueue());
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System.out.println(cq.deQueue());
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System.out.println(cq.isFull());
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System.out.println(cq.isEmpty());
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cq.enQueue(6);
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cq.enQueue(7);
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cq.enQueue(8);
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System.out.println(cq.peek());
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System.out.println(cq.peek());
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cq.deleteQueue();
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}
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}
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class circularQueue{
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int[] arr;
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int topOfQueue;
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int beginningOfQueue;
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int size;
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public circularQueue(int size){
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arr=new int[size];
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topOfQueue=-1;
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beginningOfQueue=-1;
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this.size=size;
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}
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public boolean isEmpty(){
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if(beginningOfQueue==-1){
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return true;
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}else{
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return false;
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}
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}
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public boolean isFull(){
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if(topOfQueue+1==beginningOfQueue){
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return true;
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}else if(topOfQueue==size-1 && beginningOfQueue==0){
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return true;
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}else{
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return false;
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}
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}
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public void enQueue(int value){
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if(isFull()){
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System.out.println("The Queue is full!");
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}
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else if(isEmpty()) {
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beginningOfQueue=0;
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topOfQueue++;
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arr[topOfQueue]=value;
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System.out.println(value+" has been successfully inserted!");
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}else{
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if(topOfQueue+1==size){
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topOfQueue=0;
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}else{
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topOfQueue++;
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}
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arr[topOfQueue]=value;
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System.out.println(value+" has been successfully inserted!");
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}
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}
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public int deQueue(){
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if(isEmpty()){
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System.out.println("The Queue is Empty!");
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return -1;
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}else{
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int res= arr[beginningOfQueue];
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arr[beginningOfQueue]=Integer.MIN_VALUE;
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if(beginningOfQueue==topOfQueue){
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beginningOfQueue=topOfQueue=-1;
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}else if(beginningOfQueue+1==size){
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beginningOfQueue=0;
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}else{
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beginningOfQueue++;
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}
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return res;
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}
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}
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public int peek(){
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if(isEmpty()){
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System.out.println("The Queue is Empty!");
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return -1;
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}else{
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return arr[beginningOfQueue];
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}
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}
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public void deleteQueue(){
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arr=null;
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System.out.println("The Queue is deleted!");
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}
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}
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