< Previous 　　　　　　　　　　　　　　　　 Next >

Given n nodes labeled from 0 to n-1 and a list of undirected edges (each edge is a pair of nodes), write a function to check whether these edges make up a valid tree.

Example 1:

Input: n = 5, and edges = [[0,1], [0,2], [0,3], [1,4]]
Output: true

Example 2:

Input: n = 5, and edges = [[0,1], [1,2], [2,3], [1,3], [1,4]]
Output: false

Note: you can assume that no duplicate edges will appear in edges. Since all edges are undirected, [0,1] is the same as [1,0] and thus will not appear together in edges.

[Depth-First Search] [Breadth-First Search] [Union Find] [Graph]

1. Course Schedule (Medium)
2. Number of Connected Components in an Undirected Graph (Medium)
3. Keys and Rooms (Medium)