From 3fb5c48ee5ede80b26b6c42c59303f3c78f1b835 Mon Sep 17 00:00:00 2001
From: Zengtudor <zengtudor@outlook.com>
Date: Tue, 17 Sep 2024 20:04:21 +0800
Subject: [PATCH] update

---
 20240823/十四届蓝桥比赛/简单算术题.cpp |  1 +
 20240917/P1991/P1991.cpp               | 93 ++++++++++++++++++++++++++
 xmake.lua                              |  7 +-
 3 files changed, 99 insertions(+), 2 deletions(-)
 create mode 100644 20240917/P1991/P1991.cpp

diff --git a/20240823/十四届蓝桥比赛/简单算术题.cpp b/20240823/十四届蓝桥比赛/简单算术题.cpp
index c223807..58b773c 100644
--- a/20240823/十四届蓝桥比赛/简单算术题.cpp
+++ b/20240823/十四届蓝桥比赛/简单算术题.cpp
@@ -1,4 +1,5 @@
 #include<iostream>
+#include<stack>
 using namespace std;
 typedef long long ll;
 
diff --git a/20240917/P1991/P1991.cpp b/20240917/P1991/P1991.cpp
new file mode 100644
index 0000000..69757cc
--- /dev/null
+++ b/20240917/P1991/P1991.cpp
@@ -0,0 +1,93 @@
+#include <algorithm>
+#include <cmath>
+#include <iomanip>
+#include <ios>
+#include <iostream>
+#include <istream>
+
+const int MAX_P = 500+5;
+
+struct Dir{
+    int x,y;
+};
+
+struct Edge{
+    int s,e;
+    double dis;
+    bool operator<(const Edge that)const {
+        return this->dis < that.dis;
+    }
+}edges[MAX_P*MAX_P];
+
+
+int s,p;
+Dir dirs[MAX_P];
+
+decltype(Edge::dis) square(const decltype(Edge::dis) &n){
+    return n*n;
+}
+
+int check_sets[MAX_P];
+
+int find_set(const int n){
+    if(check_sets[n]==n){
+        return n;
+    }else{
+        check_sets[n] = find_set(check_sets[n]);
+    }
+    return check_sets[n];
+}
+
+void merge_set(const int a,const int b){
+    check_sets[find_set(a)] = check_sets[find_set(b)];
+}
+
+int main(){
+    std::cin.sync_with_stdio(false),std::cin.tie(0),std::cout.tie(0);
+
+    std::cin>>s>>p;
+
+    for(int i=1;i<=p;i++){
+        check_sets[i]=i;
+    }
+
+    for(int i=1;i<=p;i++){
+        std::cin>>dirs[i].x>>dirs[i].y;
+    }
+
+    int flag = -1;
+    for(int i=1;i<=p;i++){
+        for(int j=i+1;j<=p;j++){
+            flag++;
+            edges[flag].e=i,edges[flag].s=j,edges[flag].dis=std::sqrt(square(dirs[i].x-dirs[j].x)+square(dirs[i].y-dirs[j].y));
+        }
+    }
+
+    std::sort(edges,edges+flag+1);
+
+    decltype(Edge::dis) ans{0};
+
+    // #define NV(v)std::cout<<#v<<" : "<<(v)<<"\n";
+    #define NV(v)
+
+    int cnt{0};
+
+    for(int i=0;i<flag;i++){
+        NV(find_set(edges[i].e));
+        NV(find_set(edges[i].s));
+
+        if(find_set(edges[i].e)!=find_set(edges[i].s)){
+            NV(edges[i].dis)
+            merge_set(edges[i].e,edges[i].s);
+            // std::cout<<"merge "<<edges[i].e<<" "<<edges[i].s<<"\n";
+            ans=edges[i].dis;
+            cnt++;
+            if(cnt>=p-s){
+                std::cout<<std::fixed<<std::setprecision(2)<<ans<<"\n";
+                return 0;
+            }   
+        }
+    }
+}
+
+    
\ No newline at end of file
diff --git a/xmake.lua b/xmake.lua
index 35baf30..78425bc 100644
--- a/xmake.lua
+++ b/xmake.lua
@@ -7,7 +7,7 @@ end
 if is_mode("release") and (is_plat("linux")or is_plat("mingw")) then 
     add_cxxflags("-march=native")
 end 
-set_languages("c++latest")
+set_languages("c++23")
 set_warnings("all")
 
 target("P1158")
@@ -60,4 +60,7 @@ target("oj1808")
     add_files("20240915/1808/1808.cpp")
 
 target("matchStr")
-    add_files("20240915/matchStr/*.cpp")
\ No newline at end of file
+    add_files("20240915/matchStr/*.cpp")
+
+target("P1991")
+    add_files("20240917/P1991/P1991.cpp")
\ No newline at end of file