From 63a72b5f14f8d0f16be2d331d40dc87124ce1142 Mon Sep 17 00:00:00 2001
From: Zengtudor <Zengtudor@outlook.com>
Date: Sun, 12 Oct 2025 09:43:37 +0800
Subject: [PATCH] =?UTF-8?q?feat:=20=E6=B7=BB=E5=8A=A0P3879=E9=A2=98?=
 =?UTF-8?q?=E7=9B=AE=E8=A7=A3=E7=AD=94=E5=AE=9E=E7=8E=B0?=
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实现一个基于map和set的字符串索引系统，用于快速查询包含特定字符串的文档ID。通过同步输入输出流提高性能，适用于大规模数据处理场景。
---
 src/10/12/P3879.cpp | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
 create mode 100644 src/10/12/P3879.cpp

diff --git a/src/10/12/P3879.cpp b/src/10/12/P3879.cpp
new file mode 100644
index 0000000..bfab136
--- /dev/null
+++ b/src/10/12/P3879.cpp
@@ -0,0 +1,35 @@
+#include <cstdint>
+#include <iostream>
+#include <istream>
+#include <map>
+#include <set>
+#include <string>
+using ll = int64_t;
+
+ll n,m,l;
+std::map<std::string,std::set<ll>> s;
+std::string tmp;
+
+int main(){
+    std::iostream::sync_with_stdio(false);
+    std::cin.tie(nullptr);
+
+    std::cin>>n;
+    for(ll i=1;i<=n;i++){
+        std::cin>>l;
+        for(ll j=1;j<=l;j++){
+            std::cin>>tmp;
+            s[tmp].insert(i);
+        }
+    }
+    std::cin>>m;
+    while(m--){
+        std::cin>>tmp;
+        if(const auto p = s.find(tmp);p!=s.end()){
+            for(const ll i:p->second){
+                std::cout<<i<<" ";
+            }
+        }
+        std::cout<<"\n";
+    }
+}
\ No newline at end of file