Skip to main content

Binary Tree Right Side View

Question​

What is the order of the nodes from right to left when viewed from the right side of a binary tree?

Example 1
Input: 
     1
    / \
   2   3
  / \   \
 4   5   6

Output: [1, 3, 6]

Solution​

all//Binary Tree Right Side View.py


# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def rightSideView(self, root):
        res = []
        if not root:
            return res

        queue = [root]
        while queue:
            level_size = len(queue)
            for i in range(level_size):
                cur_node = queue.pop(0)

                if i == level_size - 1:
                    res.append(cur_node.val)

                if cur_node.left:
                    queue.append(cur_node.left)
                if cur_node.right:
                    queue.append(cur_node.right)

        return res