323. Number of Connected Components in an Undirected Graph (M)

You have a graph of n nodes. You are given an integer n and an array edges where edges[i] = [ai, bi] indicates that there is an edge between ai and bi in the graph.

Return the number of connected components in the graph.

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

• 1 <= edges.length <= 5000

• edges[i].length == 2

• 0 <= ai <= bi < n

• ai != bi

• There are no repeated edges.

Solution: