From a36a2f6976c3bd0dd22bbab8be5db7c499581379 Mon Sep 17 00:00:00 2001
From: Baoshuo <i@baoshuo.ren>
Date: Fri, 24 Jun 2022 19:47:02 +0800
Subject: [PATCH] =?UTF-8?q?P2731=20[USACO3.3]=E9=AA=91=E9=A9=AC=E4=BF=AE?=
 =?UTF-8?q?=E6=A0=85=E6=A0=8F=20Riding=20the=20Fences?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

https://www.luogu.com.cn/record/77837475
---
 Luogu/P2731/P2731.cpp        | 61 ++++++++++++++++++++++++++++++++++++
 Luogu/P2731/data/P2731_8.in  |  3 ++
 Luogu/P2731/data/P2731_8.out |  3 ++
 3 files changed, 67 insertions(+)
 create mode 100644 Luogu/P2731/P2731.cpp
 create mode 100644 Luogu/P2731/data/P2731_8.in
 create mode 100644 Luogu/P2731/data/P2731_8.out

diff --git a/Luogu/P2731/P2731.cpp b/Luogu/P2731/P2731.cpp
new file mode 100644
index 00000000..f231c45f
--- /dev/null
+++ b/Luogu/P2731/P2731.cpp
@@ -0,0 +1,61 @@
+#include <iostream>
+#include <algorithm>
+#include <limits>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 505;
+
+int m, g[N][N], d[N];
+int min = std::numeric_limits<int>::max(),
+    max = std::numeric_limits<int>::min();
+int cnt, ans[N << 2];
+
+void dfs(int u) {
+    for (int i = min; i <= max; i++) {
+        if (g[u][i]) {
+            g[u][i]--, g[i][u]--;
+
+            dfs(i);
+        }
+    }
+
+    ans[++cnt] = u;
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> m;
+
+    while (m--) {
+        int u, v;
+
+        cin >> u >> v;
+
+        g[u][v]++, g[v][u]++;
+        d[u]++, d[v]++;
+
+        min = std::min({min, u, v});
+        max = std::max({max, u, v});
+    }
+
+    int s = min;
+    for (int i = min; i <= max; i++) {
+        if (d[i] & 1) {
+            s = i;
+            break;
+        }
+    }
+
+    dfs(s);
+
+    for (int i = cnt; i; i--) {
+        cout << ans[i] << endl;
+    }
+
+    return 0;
+}
diff --git a/Luogu/P2731/data/P2731_8.in b/Luogu/P2731/data/P2731_8.in
new file mode 100644
index 00000000..0e987dd4
--- /dev/null
+++ b/Luogu/P2731/data/P2731_8.in
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:5fd7b39dbd43b341a50d0468f34b12fef4170e4a5a0b084387680308fe2f944b
+size 8762
diff --git a/Luogu/P2731/data/P2731_8.out b/Luogu/P2731/data/P2731_8.out
new file mode 100644
index 00000000..a6ec6d84
--- /dev/null
+++ b/Luogu/P2731/data/P2731_8.out
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e469449c6a4b17494c183d0ba5295454d2ade69d8ff767e179739e0d8f95a26a
+size 4895