import java.awt.HeadlessException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import javax.xml.soap.Node;
public class Deque<Item> implements Iterable<Item> {
private int size;
private Node<Item> head;
private Node<Item> tail;
private static class Node<Item> {
private Item key;
private Node<Item> leftNode;
private Node<Item> rightNode;
Node(Item key, Node<Item> left, Node<Item> right) {
this.key = key;
this.leftNode = left;
this.rightNode = right;
}
}
public Deque() {
head = new Node<Item>(null,null,null);
tail = new Node<Item>(null,head,null);
head.rightNode = tail;
size = 0;
}
public boolean isEmpty() {
return head.rightNode == tail;
}
public int size() {
return size;
}
public void addFirst(Item item) {
if (item == null) throw new NullPointerException(" trying to add nothing");
else {
Node<Item> oldFirstNode = head.rightNode;
head.rightNode = new Node<Item>(item,head,oldFirstNode);
oldFirstNode.leftNode = head.rightNode;
size++;
}
}
public void addLast(Item item) {
if (item == null) throw new NullPointerException(" trying to add nothing");
else {
Node<Item> oldLastNode = tail.leftNode;
tail.leftNode = new Node<Item>(item,oldLastNode,tail);
oldLastNode.rightNode = tail.leftNode;
size++;
}
}
public Item removeFirst() { // remove and return the item from the front
if (isEmpty()) throw new NoSuchElementException(" Deque is alrady empty");
else {
Node<Item> delete = head.rightNode;
Node<Item> newFirstNode = head.rightNode.rightNode;
newFirstNode.leftNode = head;
head.rightNode = newFirstNode;
delete.leftNode = null;
delete.rightNode = null;
Item myKeyItem = delete.key;
delete = null;
size--;
return myKeyItem;
}
}
public Item removeLast() { // remove and return the item from the end
if (isEmpty()) throw new NoSuchElementException(" Deque is alrady empty");
else {
Node<Item> delete = tail.leftNode;
Node<Item> newLastNode = tail.leftNode.leftNode;
newLastNode.rightNode = tail;
tail.leftNode = newLastNode;
delete.leftNode = null;
delete.rightNode = null;
Item myKeyItem = delete.key;
delete = null;
size--;
return myKeyItem;
}
}
public Iterator<Item> iterator() { // return an iterator over items in order from front to end
return new DequeIterator();
}
private class DequeIterator implements Iterator<Item> {
private Node<Item> current = head.rightNode;
public boolean hasNext() {return current != tail;}
public void remove() { throw new UnsupportedOperationException("not yet"); }
public Item next() {
if (!hasNext()) throw new NoSuchElementException("no next");
Item key = current.key;
current = current.rightNode;
return key;
}
}
public static void main(String[] args) {
Deque<Integer>[] s = new Deque[10];
for (int i = 0; i < 10; i++) {
s[i] =new Deque<Integer>(); // initial each object
}
s[0].addFirst(1);
// s[1].addFirst(2);
StdOut.print(s[0]);
//StdOut.print(s[1]);
}
}
In the following code I have a compiling error stats that "Cannot instantiate the type Deque".
package Assign3;
import java.util.Deque;
public class graph {
//private Deque<Integer>[] graphRepDeques;
final static int Amount = 200;
private Deque<Integer>[] s = new Deque[Amount];
public graph(String filename) {
In in = new In(filename);
//final int Amount = 200;
s = new Deque[Amount];
for (int i = 0; i < Amount; i++) {
String[] currentLine = in.readLine().split("\\s");
int size = currentLine.length;
s[i] =new Deque<Integer>(); // why Cannot instantiate the type Deque<Integer>???????
for (int j = 1; j < size; j++) {
int temp = Integer.parseInt(currentLine[j]);
s[i].add(temp);
}
}
}
private void show() {
for (int i = 0; i < Amount; i++) {
for (int a: s[i]) {
//StdOut.print(a + " ");
}
}
}
public static void main(String[] args) {
graph a = new graph("kargerMinCut.txt"); //whatever text you like with integers
a.show();
}
}
The error I got is
Cannot instantiate the type Deque<Integer>
I can instantiate Deque in the main function in class "Deque", but why I cannot do it in class "graph"? Very confused here
I appreciate any help thanks.
The goal of my code is to read the numbers in a file line by line and for each line, I store the numbers I got into a object of class Deque. Therefore, I need an array of objects of Deque to store all the numbers. Similary to an array of linkedlist (Deque in my code).
The problem is I do not know how to initialized an array of this linkedlist (Deque in my code) properly so I can "push" all the keys in each linkedlist (Deque)
