Number of Connected Components in an Undirected Graph

Medium

Given n nodes labeled 0..n-1 and a list of undirected edges, return the number of connected components.

Example 1

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

Example 2

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

Constraints

• 1 <= n <= 2000
• 0 <= edges.length <= 5000