add recursive path find demo

add demo for creating new thred

src/recursive/TreeNode.java

@@ -0,0 +1,43 @@
+package recursive;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class TreeNode {
+
+    private final int id;
+
+    private final int parentId;
+
+    private final String name;
+
+    private final List<TreeNode> children;
+
+    public TreeNode(int id, int parentId, String name) {
+        this.id = id;
+        this.parentId = parentId;
+        this.name = name;
+        children = new ArrayList<>();
+    }
+
+    public void addChild(TreeNode child) {
+        children.add(child);
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public int getParentId() {
+        return parentId;
+    }
+
+    @Override
+    public String toString() {
+        return "TreeNode{" +
+                "id=" + id +
+                ", parentId=" + parentId +
+                ", children=" + children.toString() +
+                '}';
+    }
+}