#2104. 【模板】割点（割顶）

https://sjzezoj.com/submission/74885

S2OJ/2104/2104.cpp

@@ -0,0 +1,68 @@
+#include <iostream>
+#include <algorithm>
+#include <vector>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 2e4 + 5;
+
+int n, m;
+std::vector<int> g[N];
+int root, cnt, dfn[N], low[N];
+bool cut[N];
+
+void tarjan(int u) {
+    dfn[u] = low[u] = ++cnt;
+    bool flag = false;
+
+    for (int v : g[u]) {
+        if (!dfn[v]) {
+            tarjan(v);
+            low[u] = std::min(low[u], low[v]);
+            if (dfn[u] <= low[v]) {
+                if (u != root || flag) {
+                    cut[u] = true;
+                } else {
+                    flag = true;
+                }
+            }
+        } else {
+            low[u] = std::min(low[u], dfn[v]);
+        }
+    }
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> m;
+
+    for (int i = 1, x, y; i <= m; i++) {
+        cin >> x >> y;
+
+        g[x].emplace_back(y);
+        g[y].emplace_back(x);
+    }
+
+    for (int i = 1; i <= n; i++) {
+        if (!dfn[i]) {
+            root = i;
+            tarjan(i);
+        }
+    }
+
+    cout << std::count(cut + 1, cut + n + 1, true) << endl;
+
+    for (int i = 1; i <= n; i++) {
+        if (cut[i]) {
+            cout << i << ' ';
+        }
+    }
+
+    cout << endl;
+
+    return 0;
+}

S2OJ/2104/resources/gen.cpp

@@ -0,0 +1,51 @@
+/**
+ * @file S2OJ/2104/gen.cpp
+ * @author Baoshuo <i@baoshuo.ren>
+ * @url https://baoshuo.ren
+ * @license GPL-3.0
+ * @date 2023-03-30
+ */
+
+#include "testlib.h"
+
+#include <iostream>
+#include <limits>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+#define N_TESTS 25
+#define PERCENT_TESTS(_percent) (static_cast<double>(_percent) / 100 * N_TESTS)
+
+int main(int argc, char* argv[]) {
+    registerGen(argc, argv, 1);
+
+    int id = opt<int>("id");
+
+    int min_n = 10000,
+        max_n = 20000;
+    int min_m = 50000,
+        max_m = 100000;
+
+    if (id <= PERCENT_TESTS(30)) {
+        min_n = 500, max_n = 1000;
+        min_m = 1000, max_m = 5000;
+    } else {  // all tests
+        // (none)
+    }
+
+    int n = rnd.next(min_n, max_n);
+    int m = rnd.next(min_m, max_m);
+
+    cout << n << ' ' << m << endl;
+
+    for (int i = 1; i <= m; i++) {
+        int u = rnd.next(1, n);
+        int v = rnd.next(1, n);
+
+        cout << u << ' ' << v << endl;
+    }
+
+    return 0;
+}