LeetCode 75 C++ | Step-by-Step Solutions (LAN Academy) - LeetCode 399 – Evaluate Division (C++ Graph)

In this video we solve LeetCode 399: “Evaluate Division” using C++ and a clean graph + DFS/BFS approach. We are given equations like a / b = k and we need to answer queries of the form x / y = ? This is a perfect problem to learn how to model relationships as a weighted graph. What you will learn: • How to build a graph where each variable is a node and each equation is a weighted edge • Why this is basically a path search with product of weights • How to use DFS or BFS to answer each query • How to handle unknown variables and disconnected components • Full C++ implementation, step by step • Time and space complexity analysis 🔗 Problem link: https://leetcode.com/problems/evaluate-division/ 📚 Watch the full LeetCode 75 playlist (C++ explanations + animations): https://www.youtube.com/playlist?list=PLF0G-7pZcOza_jyAxwMpa5KnK3vST5smK ––––– ⏱ Timestamps (adjust after editing) 00:00 Intro & problem statement 01:00 Turning equations into a graph 04:00 DFS/BFS idea – path product = division result 08:00 Implementing the graph in C++ (adjacency list) 13:00 Answering queries with DFS/BFS 18:00 Handling unknown variables / no path case 20:00 Time and space complexity 21:00 Recap and next problems to try ––––– 💻 Technologies used • Language: C++ • Topic: Graphs, DFS, BFS, weighted graph • Difficulty: Medium • Use case: Interview prep, LeetCode practice ––––– If this helped you, consider: 👍 Liking the video 📝 Commenting which graph problem you want next ✅ Subscribing for more C++ + algorithms explanations Follow LAN Academy Website: https://lanacademy-school.thinkific.com YouTube: @lanacademy9521 Twitter: https://x.com/SolutionsLan #leetcode #leetcode399 #cpp #graph #dfs #bfs #codinginterview