323. Number of Connected Components in an Undirected Graph

1function countComponents(n: number, edges: number[][]): number {
2  const parent = Array.from({ length: n }, (_, i) => i);
3  const find = (x: number): number => (parent[x] === x ? x : (parent[x] = find(parent[x])));
4  let count = n;
5  for (const [a, b] of edges) {
6    const ra = find(a), rb = find(b);
7    if (ra !== rb) { parent[ra] = rb; count--; }
8  }
9  return count;
10}

6 singleton sets.

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