Connect Nodes at same level

'''
class Node:
    def __init__(self, val):
        self.right = None
        self.data = val
        self.left = None
        self.nextRight = None
'''
'''
Logic: Used BFS traversal level by level.Stored nodes in deque and connected each node's nextRight to its adjacent right node in the same level.
TC: O(N), Every node is visited once.
'''

from collections import deque
class Solution:
    def connect(self, root):
        if not root:
            return
        q = deque()
        q.append(root)
        while q:
            k = len(q)
            for i in range(k):
                temp = q.popleft()

                # last node of current level
                if i == k - 1:
                    temp.nextRight = None
                else:
                    temp.nextRight = q[0]

                if temp.left:
                    q.append(temp.left)
                if temp.right:
                    q.append(temp.right)