RosettaCodeData/Task/Tree-traversal/Java/tree-traversal.java

106 lines
2.1 KiB
Java

import java.util.Queue;
import java.util.LinkedList;
public class TreeTraverse
{
private static class Node<T>
{
public Node<T> left;
public Node<T> right;
public T data;
public Node(T data)
{
this.data = data;
}
public Node<T> getLeft()
{
return this.left;
}
public void setLeft(Node<T> left)
{
this.left = left;
}
public Node<T> getRight()
{
return this.right;
}
public void setRight(Node<T> right)
{
this.right = right;
}
}
public static void preorder(Node<?> n)
{
if (n != null)
{
System.out.print(n.data + " ");
preorder(n.getLeft());
preorder(n.getRight());
}
}
public static void inorder(Node<?> n)
{
if (n != null)
{
inorder(n.getLeft());
System.out.print(n.data + " ");
inorder(n.getRight());
}
}
public static void postorder(Node<?> n)
{
if (n != null)
{
postorder(n.getLeft());
postorder(n.getRight());
System.out.print(n.data + " ");
}
}
public static void levelorder(Node<?> n)
{
Queue<Node<?>> nodequeue = new LinkedList<Node<?>>();
if (n != null)
nodequeue.add(n);
while (!nodequeue.isEmpty())
{
Node<?> next = nodequeue.remove();
System.out.print(next.data + " ");
if (next.getLeft() != null)
{
nodequeue.add(next.getLeft());
}
if (next.getRight() != null)
{
nodequeue.add(next.getRight());
}
}
}
public static void main(final String[] args)
{
Node<Integer> one = new Node<Integer>(1);
Node<Integer> two = new Node<Integer>(2);
Node<Integer> three = new Node<Integer>(3);
Node<Integer> four = new Node<Integer>(4);
Node<Integer> five = new Node<Integer>(5);
Node<Integer> six = new Node<Integer>(6);
Node<Integer> seven = new Node<Integer>(7);
Node<Integer> eight = new Node<Integer>(8);
Node<Integer> nine = new Node<Integer>(9);
one.setLeft(two);
one.setRight(three);
two.setLeft(four);
two.setRight(five);
three.setLeft(six);
four.setLeft(seven);
six.setLeft(eight);
six.setRight(nine);
preorder(one);
System.out.println();
inorder(one);
System.out.println();
postorder(one);
System.out.println();
levelorder(one);
System.out.println();
}
}