217. Number of Connected Components in an Undirected Graph

MediumGraph

You have a graph of n nodes labeled from 0 to n - 1. You are given an integer n and an array edges where edges[i] = [a_i, b_i] indicates that there is an edge between a_i and b_i in the graph. Return the number of connected components in the graph.

Examples

Input: 5 [[0,1],[1,2],[3,4]]

Output: 2

Explanation: Nodes {0,1,2} form one component and {3,4} another; node counting via union-find gives 2.

Constraints

1 <= n <= 2000
0 <= edges.length <= 5000
edges[i].length == 2
0 <= a_i, b_i < n
a_i != b_i
There are no repeated edges.

Run checks all cases above. Submit evaluates all test cases.