P5227 [AHOI2013]连通图

https://www.luogu.com.cn/record/101799398

Luogu/P5227/P5227.cpp

@@ -0,0 +1,99 @@
+#include <iostream>
+#include <algorithm>
+#include <iterator>
+#include <limits>
+#include <random>
+#include <utility>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5,
+          M = 2e5 + 5;
+
+int n, m, q, s[N], d[M];
+std::mt19937 rng(std::random_device{}());
+std::vector<std::pair<int, int>> g[N];
+bool vis[N];
+
+template <typename T>
+class liner_base : private std::vector<T> {
+  public:
+    liner_base()
+        : std::vector<T>(std::numeric_limits<T>::digits + 1, 0) {}
+
+    bool insert(T w) {
+        for (int i = std::numeric_limits<T>::digits; i >= 0; --i) {
+            if (!(w >> i)) continue;
+
+            if (!this->at(i)) {
+                this->at(i) = w;
+
+                return true;
+            }
+
+            w ^= this->at(i);
+        }
+
+        return false;
+    }
+};
+
+void dfs(int u, int f) {
+    vis[u] = true;
+
+    for (auto e : g[u]) {
+        int v = e.first,
+            id = e.second;
+
+        if (!vis[v]) {
+            dfs(v, u);
+
+            s[u] ^= s[v];
+            d[id] ^= s[v];
+        } else if (v != f && !d[id]) {
+            d[id] = rng();
+
+            s[u] ^= d[id];
+            s[v] ^= d[id];
+        }
+    }
+}
+
+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].emplace_back(v, i);
+        g[v].emplace_back(u, i);
+    }
+
+    dfs(1, 1);
+
+    cin >> q;
+
+    while (q--) {
+        int c;
+        liner_base<int> lb;
+        bool ans = true;
+
+        cin >> c;
+
+        for (int i = 1, x; i <= c; i++) {
+            cin >> x;
+
+            ans &= lb.insert(d[x]);
+        }
+
+        cout << (ans ? "Connected" : "Disconnected") << endl;
+    }
+
+    return 0;
+}