From d7c1104f8b17b9a1a27c77c76e29d58f04e63b8b Mon Sep 17 00:00:00 2001
From: Baoshuo <i@baoshuo.ren>
Date: Fri, 28 Oct 2022 11:03:46 +0800
Subject: [PATCH] =?UTF-8?q?P3388=20=E3=80=90=E6=A8=A1=E6=9D=BF=E3=80=91?=
 =?UTF-8?q?=E5=89=B2=E7=82=B9=EF=BC=88=E5=89=B2=E9=A1=B6=EF=BC=89?=
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https://www.luogu.com.cn/record/91855549
---
 Luogu/P3388/P3388.cpp | 38 ++++++++++++++++++++++----------------
 1 file changed, 22 insertions(+), 16 deletions(-)

diff --git a/Luogu/P3388/P3388.cpp b/Luogu/P3388/P3388.cpp
index aa08af5a..be75a5bb 100644
--- a/Luogu/P3388/P3388.cpp
+++ b/Luogu/P3388/P3388.cpp
@@ -1,23 +1,22 @@
 #include <iostream>
+#include <algorithm>
 #include <vector>
 
 using std::cin;
 using std::cout;
-using std::endl;
+const char endl = '\n';
 
-const int N = 20005;
+const int N = 2e4 + 5;
 
-int n, m, x, y;
-std::vector<int> ans, g[N];
-
-// Tarjan
-int cnt, dfn[N], low[N];
-int root;
+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);
@@ -36,27 +35,34 @@ void tarjan(int u) {
 }
 
 int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
     cin >> n >> m;
-    for (int i = 1; i <= m; i++) {
+
+    for (int i = 1, x, y; i <= m; i++) {
         cin >> x >> y;
-        g[x].push_back(y);
-        g[y].push_back(x);
+
+        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]) {
-            ans.push_back(i);
+            cout << i << ' ';
         }
     }
-    cout << ans.size() << endl;
-    for (int i : ans) {
-        cout << i << ' ';
-    }
+
     cout << endl;
+
     return 0;
 }