From f49c6c79387b16902a9a5632c4981e2159de29c6 Mon Sep 17 00:00:00 2001
From: xkm <xkm@xkm.be>
Date: Thu, 11 Jun 2026 19:11:25 +0800
Subject: [PATCH] 3-B-1

---
 3-B-1/README.md |  5 +++++
 3-B-1/main.cpp  | 43 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)
 create mode 100644 3-B-1/README.md
 create mode 100644 3-B-1/main.cpp

diff --git a/3-B-1/README.md b/3-B-1/README.md
new file mode 100644
index 0000000..ea9e5ac
--- /dev/null
+++ b/3-B-1/README.md
@@ -0,0 +1,5 @@
+# 八皇后
+
+[P1219](https://www.luogu.com.cn/problem/P1219)
+
+[code](https://www.luogu.com.cn/record/138423182)
diff --git a/3-B-1/main.cpp b/3-B-1/main.cpp
new file mode 100644
index 0000000..4af2381
--- /dev/null
+++ b/3-B-1/main.cpp
@@ -0,0 +1,43 @@
+#include <iostream>
+
+using namespace std;
+
+int xie[26], nxie[26];
+int wei[13], h[13];
+int sum;
+
+void dfs(int d, int n)
+{
+    if (d == n)
+    {
+        sum++;
+        if (sum <= 3)
+        {
+            for (int i = 0; i < n; i++)
+            {
+                cout << wei[i]+1 << ' ';
+            }
+            cout << endl;
+        }
+    }
+
+    for (int i=0;i<n;i++)
+    {
+        if (!h[i] && !xie[i+d] && !nxie[n-i-1+d])
+        {
+            h[i]=xie[i+d]=nxie[n-i-1+d]=1;
+            wei[d]=i;
+            dfs(d+1,n);
+            h[i]=xie[i+d]=nxie[n-i-1+d]=0;
+        }
+    }
+}
+
+int main()
+{
+    int n;
+    cin >> n;
+    dfs(0, n);
+    cout << sum;
+    return 0;
+}