(3)
01 #include <iostream>
02 #include <vector>
03 #include <queue>
04 using namespace std;
05 typedef pair<int, int> pii;
06 int mst(const vector<vector<pii>>& graph) {
07 int n=graph.size();
08 vector<bool> visited(n, false);
09 vector<int> distances(n, (int)1e9 );
10 priority_queue<pii, vector<pii>, greater<pii>> pq;
11 distances[0]=0;
12 pq.push({0, 0});
13 while (!pq.empty()) {
14 int u = pq.top().second;
15 pq.pop();
16 if (visited[u]) continue;
17 visited[u] = true;
18 for (const auto& neighbor : graph[u]) {
19 int v = neighbor.first, weight = neighbor.second;
20 if (!visited[v] && distances[v] > weight) {
21 distances[v] = weight;
22 pq.push({distances[v], v});
23 }
24 }
25 }
26 int totalWeight = 0;
27 for (int i=0; i<n; ++i) totalWeight+=distances[i];
28 return totalWeight;
29 }
30 int main() {
31 int n, m;
32 cin >> n >> m;
33 vector<int> colors(n);
34 for (int i=0; i<n; ++i) cin>>colors[i];
35 vector<vector<pii>> graph(n);
36 for (int i=0; i<m; ++i) {
37 int u, v;
38 cin >> u >> v;
39 u--; v--;
40 int weight = (colors[u] == colors[v]) ? 1 : 0;
41 graph[u].push_back({v, weight});
42 graph[v].push_back({u, weight});
43 }
44 int ans = mst(graph);
45 cout << ans << endl;
46 return 0;
47 }
假设输入的 n,m 是不超过 1000 的自然数，完成下面的判断题和选择题：
判断题
28. 程序中使用的是 kruskal 算法。（
