Problem:
Binary Tree

A rooted binary tree is a tree with a root node in which every node has at most two children.

Your task is to write a program which reads a rooted binary tree T and prints the following information for each node u of T:

node ID of u

parent of u

sibling of u

the number of children of u

depth of u

height of u

node type (root, internal node or leaf)

If two nodes have the same parent, they are siblings. Here, if u and v have the same parent, we say u is a sibling of v (vice versa).

The height of a node in a tree is the number of edges on the longest simple downward path from the node to a leaf.

Here, the given binary tree consists of n nodes and evey node has a unique ID from 0 to n-1.

Input

The first line of the input includes an integer n, the number of nodes of the tree.

In the next n lines, the information of each node is given in the following format:

id left right

id is the node ID, left is ID of the left child and right is ID of the right child. If the node does not have the left (right) child, the left(right) is indicated by -1.

Output

Print the information of each node in the following format:

node id: parent = p, sibling = s, degree = deg, depth = dep, height = h, type

p is ID of its parent. If the node does not have a parent, print -1.

s is ID of its sibling. If the node does not have a sibling, print -1.

deg, dep and h are the number of children, depth and height of the node respectively.

type is a type of nodes represented by a string (root, internal node or leaf. If the root can be considered as a leaf or an internal node, print root.

Please follow the format presented in a sample output below.

Constraints

1 ≤ n ≤ 25

Sample Input 1

9
0 1 4
1 2 3
2 -1 -1
3 -1 -1
4 5 8
5 6 7
6 -1 -1
7 -1 -1
8 -1 -1

Sample Output 1

node 0: parent = -1, sibling = -1, degree = 2, depth = 0, height = 3, root
node 1: parent = 0, sibling = 4, degree = 2, depth = 1, height = 1, internal node
node 2: parent = 1, sibling = 3, degree = 0, depth = 2, height = 0, leaf
node 3: parent = 1, sibling = 2, degree = 0, depth = 2, height = 0, leaf
node 4: parent = 0, sibling = 1, degree = 2, depth = 1, height = 2, internal node
node 5: parent = 4, sibling = 8, degree = 2, depth = 2, height = 1, internal node
node 6: parent = 5, sibling = 7, degree = 0, depth = 3, height = 0, leaf
node 7: parent = 5, sibling = 6, degree = 0, depth = 3, height = 0, leaf
node 8: parent = 4, sibling = 5, degree = 0, depth = 2, height = 0, leaf

Reference

Introduction to Algorithms, Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and Clifford Stein. The MIT Press.

Solution in C# (judge verdict: Accepted)

using System;
using System.Linq;
using System.Text;

namespace ALDS1_7_B_BinaryTrees
{
	class Program
	{
		static void Main ( string[] args )
		{
			//input
			int dataCount = int.Parse (Console.ReadLine ());
			BinaryTree binaryTree = new BinaryTree (dataCount);

			for (int lp = 0; lp < dataCount; lp++)
			{
				int[] inputNum = Console.ReadLine ().Split (' ').Select (int.Parse).ToArray ();
				int nodeNumber = inputNum[0];
				int left = inputNum[1];
				int right = inputNum[2];

				binaryTree.NodeArray[nodeNumber].Left = left;
				binaryTree.NodeArray[nodeNumber].Right = right;

				if (left != BinaryTree.Null)
					binaryTree.NodeArray[left].Parent = nodeNumber;
				if (right != BinaryTree.Null)
					binaryTree.NodeArray[right].Parent = nodeNumber;
			}

			int root = 0;

			for (int lp = 0; lp < dataCount; lp++)
			{
				if (binaryTree.NodeArray[lp].Parent == BinaryTree.Null)
				{
					root = lp;
					break;
				}
			}

			//process
			binaryTree.SetDepth (root, 0);
			binaryTree.SetHeight (root);

			//output
			for (int lp = 0; lp < dataCount; lp++)
			{
				binaryTree.PrintNode (lp);
			}
		}
	}
}

class Node
{
	public int Parent { set; get; }
	public int Left { set; get; }
	public int Right { set; get; }
}

class BinaryTree
{
	public BinaryTree ( int capacity )
	{
		this.NodeArray = new Node[capacity];

		for (int lp = 0; lp < NodeArray.Length; lp++)
		{
			this.NodeArray[lp] = new Node ();
			this.NodeArray[lp].Parent = Null;
		}

		this.HeightArray = new int[capacity];
		this.DepthArray = new int[capacity];
	}

	public Node[] NodeArray { private set; get; }
	public int[] HeightArray { private set; get; }
	public int[] DepthArray { private set; get; }

	public const int Null = -1;

	//????????????????????????
	public int GetSibling ( int nodeNumber )
	{
		//?????????????????£??????
		if (NodeArray[nodeNumber].Parent == Null)
		{
			return Null;
		}

		int parentIndex = NodeArray[nodeNumber].Parent;

		//???????????????????´???§?????????????´?????????¨??????????????°
		bool isRight = NodeArray[parentIndex].Left != nodeNumber;
		bool isExistLeft = NodeArray[parentIndex].Left != Null;

		if (isRight && isExistLeft)
		{
			//??????????´??????????
			return NodeArray[parentIndex].Left;
		}

		//???????????????????´???§?????????????´?????????¨??????????????°
		bool isLeft = NodeArray[parentIndex].Right != nodeNumber;
		bool isExistRight = NodeArray[parentIndex].Right != Null;

		if (isLeft && isExistRight)
		{
			//??????????´??????????
			return NodeArray[parentIndex].Right;
		}

		//????????\???
		return Null;
	}
	//????????°?????????
	public int GetDegree ( int nodeNumber )
	{
		int count = 0;
		if (NodeArray[nodeNumber].Left != Null)
			count++;
		if (NodeArray[nodeNumber].Right != Null)
			count++;
		return count;
	}
	//??????????????±????????????
	public void SetDepth ( int nodeNumber, int depth )
	{
		//???????????????????????¨???????????´???
		if (nodeNumber == Null)
		{
			return;
		}

		//???????????±??????????´???????
		DepthArray[nodeNumber] = depth;

		//??±???????¶???????????????????????????±???????±???????
		SetDepth (NodeArray[nodeNumber].Left, depth + 1);

		//??±???????¶???????????????????????????±???????±???????
		SetDepth (NodeArray[nodeNumber].Right, depth + 1);
	}
	//??????????????????????????????
	public int SetHeight ( int nodeNumber )
	{
		int height = 0;
		int height2 = 0;

		//???????????¨??????????????°
		if (NodeArray[nodeNumber].Left != Null)
		{
			//?????°??§?????????????????????????´?+1????????°???????´???????
			height = SetHeight (NodeArray[nodeNumber].Left) + 1;
		}
		//???????????¨??????????????°
		if (NodeArray[nodeNumber].Right != Null)
		{
			//?????°??§?????????????????????????´?+1????????°???????´???????
			height2 = SetHeight (NodeArray[nodeNumber].Right) + 1;
		}

		//?????¨????????§????????????????????¨????????????
		return HeightArray[nodeNumber] = Math.Max (height, height2);
	}
	//?±???§?????????
	public string GetType ( int nodeNumber )
	{
		if (NodeArray[nodeNumber].Parent == Null)
			return "root";
		if (NodeArray[nodeNumber].Left == Null && NodeArray[nodeNumber].Right == Null)
			return "leaf";
		else
			return "internal node";
	}

	public void PrintNode ( int nodeNumber )
	{
		StringBuilder output = new StringBuilder (150);

		output.Append ("node " + nodeNumber + ": ");
		output.Append ("parent = " + NodeArray[nodeNumber].Parent + ", ");
		output.Append ("sibling = " + GetSibling (nodeNumber) + ", ");
		output.Append ("degree = " + GetDegree (nodeNumber) + ", ");
		output.Append ("depth = " + DepthArray[nodeNumber] + ", ");
		output.Append ("height = " + HeightArray[nodeNumber] + ", ");
		output.Append (GetType (nodeNumber));

		Console.WriteLine (output);
	}
}