From 47b49289666860941801378e0fd73a029924cc12 Mon Sep 17 00:00:00 2001
From: Zengtudor <Zengtudor@outlook.com>
Date: Tue, 21 Oct 2025 15:11:53 +0800
Subject: [PATCH] =?UTF-8?q?fix(P7299):=20=E4=BF=AE=E6=AD=A3=E7=89=9B?=
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修复牛位置交换时的gotopos更新逻辑，将结果存储从vector<ll>改为vector<set<ll>>以正确计算最终位置集合大小
---
 src/10/21/P7299.cpp | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/src/10/21/P7299.cpp b/src/10/21/P7299.cpp
index 57926d3..0fee80b 100644
--- a/src/10/21/P7299.cpp
+++ b/src/10/21/P7299.cpp
@@ -1,4 +1,5 @@
 #include <cstdint>
+#include <cstdio>
 #include <iostream>
 #include <istream>
 #include <set>
@@ -11,7 +12,8 @@ std::vector<ll> endpos;
 ll n,k;
 std::vector<ll> poscow,nposcow;
 std::vector<std::set<ll>> vispos;
-std::vector<ll> bcj,ans;
+std::vector<ll> bcj;
+std::vector<std::set<ll>> ans;
 static inline ll find(ll idx){
     if(idx==bcj[idx])return idx;
     return bcj[idx]=find(bcj[idx]);
@@ -27,7 +29,9 @@ int main(){
     std::cin>>n>>k;
     
     poscow.resize(n+1);
+    gotopos.resize(n+1);
     vispos.resize(n+1);
+    endpos.resize(n+1);
     bcj.resize(n+1);
     for(ll i=1;i<=n;i++)bcj[i]=i;
     ans.resize(n+1);
@@ -36,22 +40,23 @@ int main(){
     for(ll i=1;i<=k;i++){
         ll a,b;
         std::cin>>a>>b;
+        gotopos[poscow[a]].emplace(b);
+        gotopos[poscow[b]].emplace(a);
         std::swap(poscow[a],poscow[b]);
-        gotopos[poscow[a]].emplace(a);
-        gotopos[poscow[b]].emplace(b);
     }
     for(ll i=1;i<=n;i++){
         endpos[poscow[i]]=i;
-        gotopos[i].erase(gotopos[i].find(endpos[i]));
     }
     for(ll i=1;i<=n;i++)poscow[i]=i;
     for(ll i=1;i<=n;i++){
         merge(i, endpos[i]);
+        if(gotopos[i].size())gotopos[i].erase(gotopos[i].find(endpos[i]));
     }
     for(ll i=1;i<=n;i++){
-        ans[find(i)]+=1+gotopos[i].size();
+        ans[find(i)].emplace(i);
+        ans[find(i)].insert(gotopos[i].cbegin(),gotopos[i].cend());
     }
     for(ll i=1;i<=n;i++){
-        std::cout<<ans[i]<<"\n";
+        std::cout<<ans[find(i)].size()<<"\n";
     }
 }
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