compiler-design-eth/docs/hw1/SimpleVisitor.java
2020-01-15 23:42:51 +01:00

49 lines
1.1 KiB
Java

import java.lang.*;
abstract class TreeNode {
public int key;
public TreeNode leftchild;
public TreeNode rightchild;
public TreeNode(int k, TreeNode left, TreeNode right) {
key = k;
leftchild = left;
rightchild = right;
}
}
class BlueNode extends TreeNode {
public BlueNode(int k, TreeNode left, TreeNode right) { super(k, left, right); }
}
class GreenNode extends TreeNode {
public GreenNode(int k, TreeNode left, TreeNode right) { super(k, left, right); }
}
class Visitor {
public void visit(TreeNode node) {
System.out.print(node.key + ": ");
if (node instanceof BlueNode)
System.out.println("Blue");
else if (node instanceof GreenNode)
System.out.println("Green");
if (node.leftchild != null) visit(node.leftchild);
if (node.rightchild != null) visit(node.rightchild);
}
}
public class SimpleVisitor {
public static void main(String [] args) {
TreeNode root = new BlueNode(1,
new GreenNode(21,
new BlueNode(31, null, null),
new GreenNode(32, null, null)),
new GreenNode(22,
new BlueNode(33, null, null),
new GreenNode(34, null, null)));
Visitor v = new Visitor();
v.visit(root);
}
}