LeetCode: leetcode.com/explore/le 。给定一个图,判断其有几个连通域。 class Solution { public int countComponents(int n, int[][] edges) { if (n < 0 || edges == null) return -1; UnionFind uf = new UnionFind(n); for (var edge : edges) { // 当两个点从不连通变为连通时,...