import java.util.List;
import java.util.ArrayList;
public class BTInOrderTraversal {
private BTNode BTRoot;
public BTInOrderTraversal() {
BTRoot = new BTNode(1, null, null);
BTNode rootRight = new BTNode(2, null, null);
BTRoot.right = rootRight;
BTNode rootRightLeft = new BTNode(3, null, null);
rootRight.left = rootRightLeft;
}
public static void main(String[] args) {
BTInOrderTraversal application = new BTInOrderTraversal();
List<Integer> values = application.inorderTraversal();
System.out.println(values);
}
public List<Integer> inorderTraversal() {
List<Integer> list = new ArrayList<>();
populateList(BTRoot, list);
return list;
}
private void populateList(BTNode root, List<Integer> list) {
if (root == null) {
return;
}
if (root.left != null) {
populateList(root.left, list);
}
list.add(root.val);
if (root.right != null) {
populateList(root.right, list);
}
}
private class BTNode {
int val;
BTNode left;
BTNode right;
public BTNode(int val, BTNode left, BTNode right) {
this.val = val;
this.left = left;
this.right = right;
}
}
}