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 (Python):



"""
input:
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

output:
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
"""

import sys


class Node(object):
    def __init__(self):
        
        self.parent = -1
        self.type = 'leaf'
        self.depth = 0
        self.children = []
        self.degree = 0
        self.sibling = -1
        self.height = 0
        self.index = -1


def get_depth(v, depth=0):
    if not v.children:
        
        v.depth = depth
        return v.depth

    v.depth = depth

    left_child_idx = v.children[0]
    right_child_idx = v.children[1]
    if left_child_idx != -1:
        get_depth(node_list[left_child_idx], depth + 1)

    if right_child_idx != -1:
        get_depth(node_list[right_child_idx], depth + 1)
    return v.depth


def get_height(v):
    h1, h2 = 0, 0
    
    if not v.children:
        return 0

    left_child_idx = v.children[0]
    right_child_idx = v.children[1]
    if left_child_idx != -1:
        h1 = get_height(node_list[left_child_idx]) + 1

    if right_child_idx != -1:
        h2 = get_height(node_list[right_child_idx]) + 1

    v.height = max(h1, h2)
    return v.height


def generate_tree(_array):
    
    for each in _array:
        idx, *children = [int(x) for x in each]
        
        node_list[idx].index = idx
        if children != [-1, -1]:
            node_list[idx].type = 'internal node'
            node_list[idx].children = children
            node_list[idx].degree = 1 if (-1 in children) else 2
        else:
            
            continue

        for child_idx in children:
            
            if child_idx == -1:
                continue
            node_list[child_idx].parent = idx
            node_list[child_idx].sibling = sum(children) - child_idx

    root_idx = [x.index for x in node_list if x.parent == -1][0]
    root_node = node_list[root_idx]
    root_node.type = 'root'

    
    get_depth(root_node)
    get_height(root_node)

    return node_list


def print_result(_node):
    print('node ' + str(_node.index) + ':', end=' ')
    print('parent = ' + str(_node.parent) + ',', end=' ')
    print('sibling = ' + str(_node.sibling) + ',', end=' ')
    print('degree = ' + str(_node.degree) + ',', end=' ')
    print('depth = ' + str(_node.depth) + ',', end=' ')
    print('height = ' + str(_node.height) + ',', end=' ')
    print(_node.type)
    return None


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    array_length = int(_input[0])
    array = list(map(lambda x: x.split(), _input[1:]))
    

    node_list = [Node() for _ in range(array_length)]
    ans = generate_tree(_array=array)
    for node in ans:
        print_result(_node=node)

Solution (Python):
class Node(object):
    def __init__(self, parent, left, right):
        self.parent = parent
        self.left = left
        self.right = right
        self.height = None

    def get_type(self):
        if self.parent == -1:
            return 'root'
        elif self.left == -1 and self.right == -1:
            return 'leaf'
        else:
            return 'internal node'

    def get_depth(self):
        if self.parent == -1:
            return 0
        else:
            depth = 1
            t = Nodes[self.parent]
            while t.parent != -1:
                t = Nodes[t.parent]
                depth += 1
            return depth

    def get_height(self):
        h_left = 0
        h_right = 0
        if self.left != -1:
            h_left = Nodes[self.left].get_height() + 1
        if self.right != -1:
            h_right = Nodes[self.right].get_height() + 1
        self.height = max(h_left, h_right)
        return self.height

    def get_degree(self):
        degree = 0
        if self.left != -1:
            degree += 1
        if self.right != -1:
            degree += 1
        return degree

    def get_sigling(self):
        if self.parent == -1:
            return -1
        p = Nodes[self.parent]
        if Nodes[p.left] != self and  Nodes[p.left] != -1:
            return p.left
        if Nodes[p.right] != self and  Nodes[p.right] != -1:
            return p.right


def process_node_data(data):
    global Nodes
    num_of_elem = len(data)
    if num_of_elem != 3:
        raise ValueError
    else:
        my_id, left, right = data
        Nodes[my_id].left = left
        if left != -1:
            Nodes[left].parent = my_id
        Nodes[my_id].right = right
        if right != -1:
            Nodes[right].parent = my_id



MAX_NODES = 25
Nodes = [Node(-1, None, None) for _ in range(MAX_NODES)]  

if __name__ == '__main__':
    
    num_of_nodes = int(input())
    node_data = []
    for i in range(num_of_nodes):
        t = [int(x) for x in input().split(' ')]
        node_data.append(t)

    
    for d in node_data:
        process_node_data(d)

    
    for i in range(num_of_nodes):
        p = Nodes[i]
        print('node {0}: parent = {1}, sibling = {2}, degree = {3}, depth = {4}, height = {5}, {6}'.format(
            i, p.parent, p.get_sigling(), p.get_degree(), p.get_depth(), p.get_height(), p.get_type()
        ))

Solution (Python):
import sys

nil = -1

class Node:
    def __init__(self):
        self.parent = nil
        self.sibling = nil
        self.degree = 0
        self.left = nil
        self.right = nil
        self.depth = nil
        self.height = nil
        self.ntype = 'leaf'

def set_depth(v, depth):
    bitree[v].depth = depth

    if bitree[v].left != nil:
        set_depth(bitree[v].left, depth + 1)

    if bitree[v].right != nil:
        set_depth(bitree[v].right, depth + 1)

def set_height(v, height):
    while v != -1:
        if height > bitree[v].height:
            bitree[v].height = height
            v = bitree[v].parent
            height += 1
        else:
            break

n = int(input())
bitree = [Node() for i in range(n)]
leaves = set()

for i in range(n):
    line = [int(j) for j in input().split()]
    t_id = line[0]
    bitree[t_id].left = line[1]
    bitree[t_id].right = line[2]
    bitree[t_id].degree = (line[1] != nil) + (line[2] != nil)

    if bitree[t_id].degree > 0:
        bitree[t_id].ntype = 'internal node'

        if bitree[t_id].left != nil:
            bitree[bitree[t_id].left].parent = t_id

        if bitree[t_id].right != nil:
            bitree[bitree[t_id].right].parent = t_id

        if bitree[t_id].degree == 2:
            bitree[bitree[t_id].left].sibling = bitree[t_id].right
            bitree[bitree[t_id].right].sibling = bitree[t_id].left
    else:
        leaves.add(t_id)

for t_id in range(n):
    if bitree[t_id].parent == nil:
        bitree[t_id].ntype = 'root'
        r = t_id
        break

set_depth(r, 0)

for leaf in leaves:
    set_height(leaf, 0)

for t_id in range(n):

    print('node {}: parent = {}, sibling = {}, degree = {}, depth = {}, height = {}, {}'.format(
            t_id, bitree[t_id].parent, bitree[t_id].sibling, bitree[t_id].degree,
            bitree[t_id].depth, bitree[t_id].height, bitree[t_id].ntype))

Solution (Python):
import sys

nil = -1

class Node:
    def __init__(self):
        self.parent = nil
        self.sibling = nil
        self.degree = 0
        self.left = nil
        self.right = nil
        self.depth = nil
        self.height = nil
        self.ntype = 'leaf'

def set_depth(v, depth):
    bitree[v].depth = depth

    if bitree[v].left != nil:
        set_depth(bitree[v].left, depth + 1)

    if bitree[v].right != nil:
        set_depth(bitree[v].right, depth + 1)

def get_height(v):
    h1 = 0
    h2 = 0

    if bitree[v].left != nil:
        h1 = get_height(bitree[v].left) + 1
    if bitree[v].right != nil:
        h2 = get_height(bitree[v].right) + 1

    bitree[v].height = max(h1, h2)

    return bitree[v].height

n = int(input())
bitree = [Node() for i in range(n)]
leaves = set()

for i in range(n):
    line = [int(j) for j in input().split()]
    t_id = line[0]
    bitree[t_id].left = line[1]
    bitree[t_id].right = line[2]
    bitree[t_id].degree = (line[1] != nil) + (line[2] != nil)

    if bitree[t_id].degree > 0:
        bitree[t_id].ntype = 'internal node'

        if bitree[t_id].left != nil:
            bitree[bitree[t_id].left].parent = t_id

        if bitree[t_id].right != nil:
            bitree[bitree[t_id].right].parent = t_id

        if bitree[t_id].degree == 2:
            bitree[bitree[t_id].left].sibling = bitree[t_id].right
            bitree[bitree[t_id].right].sibling = bitree[t_id].left
    else:
        leaves.add(t_id)

for t_id in range(n):
    if bitree[t_id].parent == nil:
        bitree[t_id].ntype = 'root'
        r = t_id
        break

set_depth(r, 0)

get_height(r)

for t_id in range(n):

    print('node {}: parent = {}, sibling = {}, degree = {}, depth = {}, height = {}, {}'.format(
            t_id, bitree[t_id].parent, bitree[t_id].sibling, bitree[t_id].degree,
            bitree[t_id].depth, bitree[t_id].height, bitree[t_id].ntype))

Solution (Python):
NIL = -1
class Node:
    parent = NIL
    left = NIL
    right = NIL
    type = NIL
    depth = NIL
    sibling = NIL
    degree = NIL
    height = NIL
    
def setHeight(u):
    h1 = h2 = 0
    if T[u].right != NIL:
        h1 = setHeight(T[u].right) + 1
    if T[u].left != NIL:
        h2 = setHeight(T[u].left) + 1
    if h1 == h2 == NIL:
        return NIL
    else:
        return max(h1,h2)

def getDepth(u):
    d = 0
    while T[u].parent != NIL:
        u = T[u].parent
        d += 1
    return d

def getSibling(u):
    if T[u].parent == NIL:
        return NIL
    if T[T[u].parent].left != u and T[T[u].parent].left != NIL:
        return T[T[u].parent].left
    if T[T[u].parent].right != u and T[T[u].parent].right != NIL:
        return T[T[u].parent].right
    return NIL

def getDegree(u):
    deg = 0
    if T[u].left != NIL:
        deg += 1
    if T[u].right != NIL:
        deg += 1
    return deg

n = int(input())
T = [0]*n

for i in range(n):
    T[i] = Node()
for i in range(n):
    id,l,r = map(int,input().split())
    T[id].left = l
    T[id].right = r
    
for i in range(n):
    if T[i].left != NIL:
        T[T[i].left].parent = i
    if T[i].right != NIL:
        T[T[i].right].parent = i

for i in range(n):
    if T[i].parent == NIL:
        T[i].type = 'root'
    elif T[i].parent != NIL and (T[i].left != NIL or T[i].right != NIL):
        T[i].type = 'internal node'
    else:
        T[i].type = 'leaf'

for i in range(n):
    T[i].depth = getDepth(i)
    T[i].sibling = getSibling(i)
    T[i].degree = getDegree(i)
    T[i].height = setHeight(i)
for i in range(n):
    print('node ',i,': parent = ',T[i].parent,', sibling = ',T[i].sibling,', degree = ',T[i].degree,', depth = ',T[i].depth,', height = ',T[i].height,', ',T[i].type,sep = '')

Solution (Python):
class Tree:
    def __init__(self,parent,left,right):
        self.parent = parent
        self.left = left
        self.right = right
        self.sibling = -1
        self.degree = 0
        self.depth = -1
        self.height = -1

def getdepth(u):
    for i in range(N):
        depth = 0
        j = i
        while trees[j].parent != -1:
            j = trees[j].parent
            depth += 1
        trees[i].depth = depth

def getheight(u):
    hleft = hright = 0
    if trees[u].left != -1:
        hleft = getheight(trees[u].left) + 1
    if trees[u].right != -1:
        hright = getheight(trees[u].right) + 1

    trees[u].height = hleft if hleft > hright else hright
    return trees[u].height


N = int(input())

trees = [Tree(-1,-1,-1) for i in range(N)]
for i in range(N):
    l = list(map(int, input().split()))
    no = l[0]
    left = l[1]
    right = l[2]
    trees[no].left = left
    trees[no].right = right
    if left != -1:
        trees[left].parent = no
        trees[left].sibling = right
        trees[no].degree += 1
    if right != -1:
        trees[right].parent = no
        trees[right].sibling = left
        trees[no].degree += 1

r = 0
for i in range(N):
    if trees[i].parent == -1:
        r = i

getdepth(r)
getheight(r)

for i in range(N):
    type = ""
    if trees[i].parent == -1: type = "root"
    elif trees[i].left == -1 and trees[i].right == -1: type = "leaf"
    else: type = "internal node"

    print("node {0}: parent = {1}, sibling = {2}, degree = {3}, depth = {4}, height = {5}, {6}".format(
        i,
        trees[i].parent,
        trees[i].sibling,
        trees[i].degree,
        trees[i].depth,
        trees[i].height,
        type))

Solution (Python):
class Node:
  def __init__(self, nid, lid, rid):
    self.nid = nid
    self.lid = lid
    self.rid = rid
    self.height = 0
    self.type = "root"
    self.parent = None
    self.depth = 0

  def set_parent(self, parent):
    self.parent = parent
    self.type = "leaf" if (self.lid < 0 and self.rid < 0) else "internal node"
    parent.update_height(self.height + 1)

  def update_height(self, h):
    self.height = max(self.height, h)
    if self.parent: self.parent.update_height(self.height + 1)

  def get_sibling(self):
    if self.parent is None: return - 1
    if self.parent.lid == self.nid: return self.parent.rid
    if self.parent.rid == self.nid: return self.parent.lid

  def get_depth(self):
    if self.depth: return self.depth
    if self.type == "root": return 0
    self.depth = self.parent.get_depth() + 1
    return self.depth

  def get_degree(self):
    deg = 0
    if self.lid >= 0: deg += 1
    if self.rid >= 0: deg += 1
    return deg

  def display(self):
    print("node {}: parent = {}, sibling = {}, degree = {}, depth = {}, height = {}, {}".format(
      self.nid,
      self.parent.nid if self.parent else -1,
      self.get_sibling(),
      self.get_degree(),
      self.get_depth(),
      self.height,
      self.type
      )
    )

nodelist = {}
for i in range(int(input())):
  nid, lid, rid = list(map(int, input().split()))
  nodelist[nid] = Node(nid, lid, rid)

for i in nodelist:
  n = nodelist[i]
  if n.lid >= 0: nodelist[n.lid].set_parent(n)
  if n.rid >= 0: nodelist[n.rid].set_parent(n)

for i in sorted(nodelist): nodelist[i].display()

Solution (Python):
class Tree:
    def __init__(self, n):
        self.n = n
        self.nodes = [Node(i) for i in range(n)]
        self.root = -1

    def set_tree(self):
        for _ in range(self.n):
            i_str = [int(i) for i in input().split()]
            for i in range(2):
                if i_str[i+1] != -1:
                    self.nodes[i_str[0]].degree += 1
                    self.nodes[i_str[i+1]].parent = i_str[0]
                    if self.nodes[i_str[i+1]].type != "internal node":
                        self.nodes[i_str[i+1]].type = "leaf"
            if self.nodes[i_str[0]].degree == 2:
                self.nodes[i_str[1]].sibling = i_str[2]
                self.nodes[i_str[2]].sibling = i_str[1]
            if self.nodes[i_str[0]].degree > 0:
                self.nodes[i_str[0]].type = "internal node"

    def set_depth_height(self):
        self.set_root()
        self.set_depth(self.root)

        for node in self.nodes:
            if node.type == "leaf":
                self.set_height(node.id)

    def set_depth(self, parent, depth = -1):
        self.nodes[parent].depth = depth + 1
        for node in self.nodes:
            if node.parent == parent:
                self.set_depth(node.id, depth + 1)

    def set_height(self, child, height = -1):
        if self.nodes[child].height <= height + 1:
            self.nodes[child].height = height + 1
            if self.nodes[child].parent != -1:
                self.set_height(self.nodes[child].parent, height + 1)

    def set_root(self):
        for tn in self.nodes:
            if tn.parent == -1:
                self.root = tn.id
                tn.type = "root"
                break

    def show_tree_info(self):
        for node in self.nodes:
            node.show_node_info()

class Node:
    def __init__(self, id):
        self.id = id
        self.parent = -1
        self.sibling = -1
        self.degree = 0
        self.depth = 0
        self.height = 0
        self.type = "root"

    def show_node_info(self):
        print("node {0}: parent = {1}, sibling = {2}, degree = {3}, depth = {4}, height = {5}, {6}"\
        .format(self.id, self.parent, self.sibling, self.degree, self.depth, self.height, self.type))

if __name__ == '__main__':
    tree = Tree(int(input()))
    tree.set_tree()
    tree.set_depth_height()
    tree.show_tree_info()

Solution (Python):
NIL = -1


class Node:
    right = NIL
    left = NIL
    parent = NIL


def setHeight(u):
    global T, H
    hr = 0
    hl = 0
    if T[u].right != NIL:
        hr = setHeight(T[u].right) + 1
    if T[u].left != NIL:
        hl = setHeight(T[u].left) + 1
    h = max(hr, hl)
    H[u] = h
    return h


def setDepth(u, d):
    global T, D
    D[u] = d
    if T[u].right != NIL:
        setDepth(T[u].right, d + 1)
    if T[u].left != NIL:
        setDepth(T[u].left, d + 1)


def getSibling(u):
    global T
    if T[u].parent == NIL:
        return NIL
    if T[T[u].parent].left != u and T[T[u].parent].left != NIL:
        return T[T[u].parent].left
    if T[T[u].parent].right != u and T[T[u].parent].right != NIL:
        return T[T[u].parent].right
    return NIL


def getDegree(u):
    global T
    deg = 0
    if T[u].left != NIL: deg += 1
    if T[u].right != NIL: deg += 1
    return deg


def show_info(u):
    global T, D, H
    label = ""
    if T[u].parent == NIL:
        label = 'root'
    elif T[u].left == NIL and T[u].right == NIL:
        label = 'leaf'
    else:
        label = 'internal node'
    print("node {0}: parent = {1}, sibling = {2}, degree = {3}, depth = {4}, height = {5}, {6}".format(u, T[u].parent,
                                                                                                       getSibling(u),
                                                                                                       getDegree(u),
                                                                                                       D[u],
                                                                                                       H[u], label))


if __name__ == "__main__":
    
    n = int(input())
    T, D, H = [], [], []
    root_num = NIL
    for i in range(n):
        T.append(Node())
        D.append(NIL)
        H.append(0)
    for i in range(n):
        id, r, l = map(int, input().split())
        T[id].right = r
        T[id].left = l
    for i in range(n):
        if T[i].right != NIL:
            T[T[i].right].parent = i
        if T[i].left != NIL:
            T[T[i].left].parent = i
    for i in range(n):
        if T[i].parent == NIL:
            root_num = i

    setHeight(root_num)
    setDepth(root_num, 0)
    for i in range(n):
        show_info(i)

Solution (Python):
class Node:
    def __init__(self, num, left,  right):
        self.id = num
        self.left = left
        self.right = right
        self.parent = -1
        self.brother = -1
        if self.left== -1 and self.right==-1:
        	self.child = 0
        elif self.left != -1 and self.right!=-1:
        	self.child = 2
        else:
        	self.child = 1
        self.depth = 0
        self.height = 0
        self.type = None

    def show_info(self):
        print('node {0}: parent = {1}, sibling = {2}, degree = {3}, depth = {4}, height = {5}, {6}'.format(self.id, self.parent, self.brother, self.child, self.depth, self.height, self.type))

def SetNode(I_Line):
	L = list(map(int, I_Line.split()))
	num = L[0]
	left = L[1]
	right = L[2]
	node = Node(num, left, right)
	T[num] = node
	if left != -1:
		T[-1] -= left
	if right != -1:
		T[-1] -= right

def setPBD(i,p,b,d): 
    node = T[i]
    node.parent = p
    node.brother = b
    node.depth = d
    if node.parent == -1:
        node.type = "root"
    elif node.child == 0:
        node.type = "leaf"
    else:
        node.type = "internal node"
    if node.left != -1:
        setPBD(node.left, i, node.right, node.depth + 1)
    if node.right != -1:
        setPBD(node.right, i, node.left, node.depth + 1)

def setH(i): 
    node = T[i]
    if node.left == -1:
        leftheight = 0
    else:
        leftheight = setH(node.left) + 1
    if node.right == -1:
        rightheight = 0
    else:
        rightheight = setH(node.right) + 1
    node.height = max(leftheight, rightheight)
    return node.height

n = int(input())
T = [None] * n
T.append(int(n * (n-1)/2))
for i in range(n):
    x = input()
    SetNode(x)

root = T[-1]
setPBD(root, -1, -1, 0)
setH(root)
T.pop()
for i in T:
    i.show_info()

Solution (Python):
N = int(input())
M = []

type = ['root','internal node','leaf']

class node:
    def __init__(self,idx,parent,left,right):
        self.idx = idx
        self.parent = parent
        self.left = left
        self.right= right
        
        self.sibling = -1
        self.degree= 0
        self.depth = 0
        self.height = 0
        self.type=-1

    def tostr(self):
        print('node %d: parent = %d, sibling = %d, degree = %d, depth = %d, height = %d, %s' % (self.idx, self.parent, self.sibling, self.degree, self.depth, self.height, type[self.type])) 
tree = [[] for x in range(N)]




for a in range(N):
    idx,left,right = map(int,input().strip().split(' '))
    tree[idx] = node(idx, -1, left,right)

for a in range(N):
    nd = tree[a]
    if nd.left != -1:
        tree[nd.left].parent = a
    if nd.right != -1:
        tree[nd.right].parent = a
    if nd.left !=  -1:
        tree[nd.left].sibling = nd.right
    if nd.right !=  -1:
        tree[nd.right].sibling = nd.left

    if nd.left == nd.right :
        nd.type=2
        nd.degree=0
    else:
        nd.type=1
        if nd.left == -1 or nd.right == -1:
            nd.degree = 1
        else:
            nd.degree = 2

root = ''
for a in range(N):
    if tree[a].parent == -1:
        root = a
        tree[root].type=0
    
def search(root,depth):
    root = tree[root]
    root.depth = depth
    if root.type ==  2:
        return
    else:
        if root.right == -1 and root.left == -1:
            return
        if root.right != -1:
            search(root.right,depth+1)
        if root.left != -1:
            search(root.left,depth+1)

search(root,0)

def height(root,hei):
    root = tree[root]
    if root.type==2 or (root.right == -1 and root.left == -1):
        root.height=0
        return hei
    else:
        if root.left == -1:
            return height(root.right,hei+1)
        elif root.right == -1:
            return height(root.left,hei+1)
        else:
            return max(height(root.left,hei+1),height(root.right,hei+1))
for i in range(N):
    tree[i].height=height(i,0)

for a in range(N):
    tree[a].tostr()

Solution (Python):


class Node:
    def __init__(self, ID, left, right):
        
        self.id = ID
        self.parent = -1 
        self.sibling = -1 
        self.degree = -1 
        self.depth = 0 
        self.height = 0 
        self.type = None 

        
        self.left_child = left
        self.right_child = right

def calc_depth(i):
    global node_list

    if node_list[i].depth != 0:
        return node_list[i].depth

    depth = 0
    if node_list[i].parent != -1:
        depth = calc_depth(node_list[i].parent) + 1

    node_list[i].depth = depth
    return depth


def calc_height(i):
    global node_list

    if node_list[i].height != 0:
        return node_list[i].height

    h1 = h2 = 0
    if node_list[i].right_child != -1:
        h1 = calc_height(node_list[i].right_child) + 1
    if node_list[i].left_child != -1:
        h2 = calc_height(node_list[i].left_child) + 1

    height = max(h1, h2)
    node_list[i].height = height
    return height

n = int(input())
data = [tuple(map(int, input().split())) for x in range(n)]
node_list = []

for data_row in data:
    ID, left, right = data_row
    node = Node(ID, left, right)
    node_list.append(node)

node_list.sort(key = lambda node: node.id)

for i, node in enumerate(node_list):
    left = node.left_child
    right = node.right_child
    degree = 0

    
    if left != -1:
        degree += 1
        node_list[left].parent = i
        node_list[left].sibling = right

    if right != -1:
        degree += 1
        node_list[right].parent = i
        node_list[right].sibling = left

    
    node.degree = degree

for i in range(n):
    calc_depth(i)
    calc_height(i)

    node = node_list[i]

    if node.depth == 0:
        node.type = 'root'
    elif node.height == 0:
        node.type = 'leaf'
    else:
        node.type = 'internal node'

    print("node {}: parent = {}, sibling = {}, degree = {}, depth = {}, height = {}, {}".format(node.id, node.parent, node.sibling, node.degree, node.depth, node.height, node.type))

Solution (Python):


class Node:
    def __init__(self, ID, left, right):
        
        self.id = ID
        self.parent = -1 
        self.sibling = -1 
        self.degree = -1 
        self.depth = 0 
        self.height = 0 
        self.type = None 

        
        self.left_child = left
        self.right_child = right

def calc_depth(i):
    global node_list

    if node_list[i].depth != 0:
        return node_list[i].depth

    depth = 0
    if node_list[i].parent != -1:
        depth = calc_depth(node_list[i].parent) + 1

    node_list[i].depth = depth
    return depth


def calc_height(i):
    global node_list

    if node_list[i].height != 0:
        return node_list[i].height

    h1 = h2 = 0
    if node_list[i].right_child != -1:
        h1 = calc_height(node_list[i].right_child) + 1
    if node_list[i].left_child != -1:
        h2 = calc_height(node_list[i].left_child) + 1

    height = max(h1, h2)
    node_list[i].height = height
    return height

n = int(input())
data = [tuple(map(int, input().split())) for x in range(n)]
node_list = []

for data_row in data:
    ID, left, right = data_row
    node = Node(ID, left, right)
    node_list.append(node)

node_list.sort(key = lambda node: node.id)

for i, node in enumerate(node_list):
    left = node.left_child
    right = node.right_child
    degree = 0

    
    if left != -1:
        degree += 1
        node_list[left].parent = i
        node_list[left].sibling = right

    if right != -1:
        degree += 1
        node_list[right].parent = i
        node_list[right].sibling = left

    
    node.degree = degree

for i in range(n):
    calc_depth(i)
    calc_height(i)

    node = node_list[i]

    if node.depth == 0:
        node.type = 'root'
    elif node.height == 0:
        node.type = 'leaf'
    else:
        node.type = 'internal node'

    print("node {}: parent = {}, sibling = {}, degree = {}, depth = {}, height = {}, {}".format(node.id, node.parent, node.sibling, node.degree, node.depth, node.height, node.type))