Binary Tree Right Side View

Problem: Binary Tree Right Side View

We can use both breadth-first search or depth-first search to solve the problem. Each methods suits different cases. We use breadth-first search here.

Code in Python:

# Definition for a binary tree node.
# class TreeNode(object):
#     def __init__(self, x):
#         self.val = x
#         self.left = None
#         self.right = None

class Solution(object):
    def rightSideView(self, root):
        """
        :type root: TreeNode
        :rtype: List[int]
        """
        if not root: return []

        queue, res = [root], []

        while queue:
            res.append(queue[-1].val)
            next = []
            for node in queue:
                if node.left: next.append(node.left)
                if node.right: next.append(node.right)
            queue = next
        return res