How to do things

Maven: variable interpolation in POM

In general, when are we allowed to access a variable without fully qualifying it using${project.1</mavenVersion> <----- variable defined here
</properties>
<dependencies>
<dependency>
<groupId>org.

Binary tree recursion java

__3__
/ \
4 5
/ \ /
9 2 1


2 should return "01"

public String traverse(TreeNode root, TreeNode p,String s) {
if (root == p) return s;
if (root.= null) return traverse(root.