#279 Count Connected Components

Given an undirected graph with:

• n nodes (labeled from 0 to n-1)
• edges array where edges[i] = [a, b] represents an edge between nodes a and b

Return the number of connected components in the graph.

A connected component is a group of nodes where:

• Any node can reach any other node in the same component
• No node can reach nodes in different components

Constraints:

• 1 ≤ n ≤ 100
• 0 ≤ edges.length ≤ n * (n-1) / 2
• No duplicate edges
• Edges are undirected

Examples:

// Example 1:
const n1 = 3;
const edges1 = [
  [0, 1],
  [0, 2],
];
console.log(countComponents(n1, edges1));
// Output: 1
// Explanation: All nodes are connected

// Example 2:
const n2 = 6;
const edges2 = [
  [0, 1],
  [1, 2],
  [2, 3],
  [4, 5],
];
console.log(countComponents(n2, edges2));
// Output: 2
// Explanation: Nodes 0-1-2-3 form one component, 4-5 form another