https://www.luogu.org/problemnew/show/P2024

題解：

https://www.luogu.org/blog/Sooke/solution-p2024

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/* *@Author: STZG *@Language: C++ */ #include <bits/stdc++.h> #include<iostream> #include<algorithm> #include<cstdlib> #include<cstring> #include<cstdio> #include<string> #include<vector> #include<bitset> #include<queue> #include<deque> #include<stack> #include<cmath> #include<list> #include<map> #include<set> //#define DEBUG #define RI register int using namespace std; typedef long long ll; //typedef __int128 lll; const int N=100000+10; const int M=100000+10; const int MOD=1e9+7; const double PI = acos(-1.0); const double EXP = 1E-8; const int INF = 0x3f3f3f3f; int t,n,m,k,q; int ans,cnt,flag,temp,sum,a,b,c; int pre[N*3]; char str; struct node{}; int find(int x){if(x==pre[x])return x;return pre[x]=find(pre[x]);} int main() { #ifdef DEBUGfreopen("input.in", "r", stdin);//freopen("output.out", "w", stdout); #endif//ios::sync_with_stdio(false);//cin.tie(0);//cout.tie(0);//scanf("%d",&t);//while(t--){scanf("%d%d",&n,&m);for(int i=1;i<=3*n;i++)pre[i]=i;for(int i=1;i<=m;i++){scanf("%d%d%d",&c,&a,&b);if(a<=n&&b<=n){if(c==1){if(find(a)==find(b+n)||find(b)==find(a+n))ans++;else{pre[find(a)]=find(b);pre[find(a+n)]=find(b+n);pre[find(a+2*n)]=find(b+2*n);}}else{if(find(a)==find(b)||find(b+n)==find(a))ans++;else{pre[find(a+n)]=find(b);pre[find(a+2*n)]=find(b+n);pre[find(a)]=find(b+2*n);}}}else{ans++;}}cout<<ans<<endl;//}#ifdef DEBUGprintf("Time cost : %lf s\n",(double)clock()/CLOCKS_PER_SEC); #endif//cout << "Hello world!" << endl;return 0; }

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