P3452 [POI2007]BIU-Offices

https://www.luogu.com.cn/record/84334446

Luogu/P3452/P3452.cpp

@@ -0,0 +1,81 @@
+#include <iostream>
+#include <algorithm>
+#include <queue>
+#include <set>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5;
+
+int n, m, cnt, ans[N];
+std::vector<int> g[N];
+std::set<int> set;
+bool vis[N];
+
+void bfs(int x) {
+    std::queue<int> q;
+
+    set.erase(x);
+    q.push(x);
+    ans[cnt]++;
+
+    while (!q.empty()) {
+        int u = q.front();
+        q.pop();
+        vis[u] = true;
+
+        for (auto it = set.begin(); it != set.end();) {
+            int v = *it;
+
+            if (*std::lower_bound(g[u].begin(), g[u].end(), v) != v) {
+                q.push(v);
+                ans[cnt]++;
+                set.erase(it++);
+            } else {
+                it++;
+            }
+        }
+    }
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> m;
+
+    for (int i = 1, u, v; i <= m; i++) {
+        cin >> u >> v;
+
+        g[u].push_back(v);
+        g[v].push_back(u);
+    }
+
+    std::for_each(g + 1, g + n + 1, [&](auto& v) { std::sort(v.begin(), v.end()); });
+
+    for (int i = 1; i <= n; i++) {
+        set.insert(i);
+    }
+
+    for (int i = 1; i <= n; i++) {
+        if (!vis[i]) {
+            cnt++;
+            bfs(i);
+        }
+    }
+
+    std::sort(ans + 1, ans + 1 + cnt);
+
+    cout << cnt << endl;
+
+    for (int i = 1; i <= cnt; i++) {
+        cout << ans[i] << ' ';
+    }
+
+    cout << endl;
+
+    return 0;
+}