Solving LeetCode 1443: Minimum Time to Collect All Apples in a Tree with Python

Welcome to another episode of vanAmsen's coding vlog. In this episode, we tackle a challenging problem from LeetCode - "Minimum Time to Collect All Apples in a Tree" (LeetCode 1443). We'll be using Python to solve this problem and I'll walk you through my thought process, the logic behind the solution, and the actual code.

This problem is essentially a graph problem disguised as a tree problem. We're given an undirected tree consisting of n vertices, some of which have apples. Our task is to collect all the apples and return the minimum time it takes to do so. The time is calculated based on the number of edges we traverse.

The solution involves a depth-first search (DFS) traversal of the tree. We start at the root and recursively visit every node, calculating the time it takes to collect all the apples in each subtree. The key is to only traverse edges that lead to apples and to avoid unnecessary traversals.

In the second part of the video, I dive into the Python code for this problem. We start by creating an adjacency list for the tree. Then, we define a recursive DFS function that calculates the time it takes to collect all apples in a subtree. The function is designed to avoid infinite loops by not revisiting the parent node of the current node.

I hope you find this video helpful for your coding journey. If you have any questions or need further clarification, feel free to leave a comment. Don't forget to like, share, and subscribe for more coding vlogs.