#####   ######  #####    ###    #   #  ###  #   #  ######
##  ##  ##      ##  ##  ## ##   #   #   #   #   #  ##
#####   ####    #####   #   #   #   #   #   #   #  ####
##  #   ##      ##      ## ##    # #    #    # #   ##
##   #  ######  ##       ###      #    ###    #    ######

$ curl repovive.com/roadmaps/google-interview-prep-v2/coding-patterns-ii-trees-graphs-dynamic-programming/leetcode-199-binary-tree-right-side-view-implementation

░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░░█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████

#####   ######  #####    ###    #   #  ###  #   #  ######
##  ##  ##      ##  ##  ## ##   #   #   #   #   #  ##
#####   ####    #####   #   #   #   #   #   #   #  ####
##  #   ##      ##      ## ##    # #    #    # #   ##
##   #  ######  ##       ###      #    ###    #    ######

$ curl repovive.com/roadmaps/google-interview-prep-v2/coding-patterns-ii-trees-graphs-dynamic-programming/leetcode-199-binary-tree-right-side-view-implementation

Repovive

LeetCode 199 Binary Tree Right Side View - Implementation - Coding Patterns II: Trees, Graphs & Dynamic Programming | Google Interview Prep | Repovive

Repovive.

Google Interview Prep6 sections · 128 units7h total

Open in Course

LeetCode 199 Binary Tree Right Side View - Implementation

The approach

BFS with a queue. Grab the last node at each level.

function rightSideView(root):
    if not root:
        return []
    result = []
    queue = [root]
    while queue:
        levelSize = len(queue)
        for i in range(levelSize):
            node = queue.pop(0)
            if i == levelSize - 1:
                result.append(node.val)
            if node.left:
                queue.append(node.left)
            if node.right:
                queue.append(node.right)
    return result

$O(n)$ time, $O(w)$ space.