LEETCODE 129. Sum Root to Leaf Numbers | DFS & BFS approach explained

In this video, I'll be solving the LeetCode problem 129: Sum Root to Leaf Numbers, which asks us to find the sum of all numbers formed by root to leaf paths in a binary tree. We'll be using both BFS and DFS approaches to solve this problem. First, we'll start with the BFS approach, where we'll use a queue to traverse the tree level by level. We'll keep track of the current path sum and the overall sum of all root to leaf paths. We'll use a pair of node and its path sum to keep track of the nodes in the queue. We'll also handle cases where the left and right children of a node are null. We'll then return the overall sum as the answer. Next, we'll move on to the DFS approach, where we'll use recursion to traverse the tree depth-first. We'll pass the current node and its path sum to the recursive function. We'll also handle cases where the node is null, and we'll return 0 if we reach a leaf node. We'll then calculate the path sum for the current node and its children recursively. Finally, we'll return the sum of the path sums of the left and right children of the current node. By the end of this video, you'll have a good understanding of how to solve this problem using both BFS and DFS approaches. If you found this video helpful, please give it a thumbs up and consider subscribing to my channel for more LeetCode solutions and programming tutorials. 0:00 Question Explained 1:04 DFS Approach Explained 5:48 BFS Approach Explained 9:42 Code Walk Threw #LeetCode #problemsolving #algorithm #programming #datastructures #binarytree #BFS #DFS #codingtutorial #programmingtutorial #softwaredevelopment #computerscience #interviewpreparation #technicalinterview