Solution: Find Minimum Diameter After Merging Two Trees

Explore how to compute the minimum diameter of a combined tree formed by connecting two undirected trees. This lesson teaches you to apply breadth-first search twice to find each tree's diameter, then use a formula to determine the optimal minimal diameter after merging the trees. Understand adjacency list construction, BFS traversal, and how to apply these to minimize the longest path in the merged structure.

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Statement
Solution
- Time complexity
- Space complexity

Statement

You are given two undirected trees: one with $n$ nodes labeled from $0$ to $n - 1$ , and another with $m$ nodes labeled from $0$ to $m - 1$ . Their structures are defined by two $2D$ integer arrays—edges1 of length $n - 1$ for the first tree, and edges2 of length $m - 1$ for the second. Each element edges1[i] = [aᵢ, bᵢ] represents an edge between nodes $aᵢ$ and $bᵢ$ in the first tree, and similarly, edges2[i] = [uᵢ, vᵢ] represents an edge in the second tree.

Your task is to connect any node from the first tree to any one node from the second tree using a single ...