mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
100 lines
2.6 KiB
C++
100 lines
2.6 KiB
C++
#include<iostream>
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#include<cstdio>
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#include<vector>
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#include<map>
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#include<queue>
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#include<cstring>
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using namespace std;
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#define MP make_pair
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#define PB push_back
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const int N=10005;
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vector<int> mp[N],rv[N];
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map< pair<int,int>,int > vis;
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int f[N],p2i[N][N];
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int dp[N*N][2];
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int n,m;
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struct Dt{
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int v,turn;
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Dt(){}
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Dt(int _v,int _turn){ v=_v; turn=_turn; }
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};
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queue<Dt> que;
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void init(){
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int id=0;
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for(int i=1;i<=n;++i)
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for(int j=i;j<=n;++j)
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p2i[j][i]=p2i[i][j]=id++;
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for(int i=0;i<id;++i){
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mp[i].clear();
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rv[i].clear();
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}
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vis.clear();
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for(int i=0;i<id;++i){
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dp[i][0]=dp[i][1]=0;
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}
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}
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int main(){
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int T;
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scanf("%d",&T);
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while(T--){
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scanf("%d%d",&n,&m);
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init();
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for(int i=0;i<m;++i){
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for(int j=1;j<=n;++j)
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scanf("%d",&f[j]);
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for(int j=1;j<=n;++j)
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for(int k=j+1;k<=n;++k){
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int fr=p2i[j][k];
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int to=p2i[f[j]][f[k]];
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if(vis[MP(fr,to)]==0){
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mp[fr].PB(to);
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rv[to].PB(fr);
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vis[MP(fr,to)]=1;
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}
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}
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}
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for(int i=1;i<=n;++i){
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que.push(Dt(p2i[i][i],0));
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que.push(Dt(p2i[i][i],1));
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dp[p2i[i][i]][0]=dp[p2i[i][i]][1]=1;
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}
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while(!que.empty()){
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Dt now=que.front();
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que.pop();
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if(now.turn==0){
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int to=now.v;
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for(int i=0;i<rv[to].size();++i){
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int fr=rv[to][i];
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if(dp[fr][1]==0){
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int st=1;
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for(int i=0;i<mp[fr].size();++i)
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st&=dp[mp[fr][i]][0];
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dp[fr][1]=st;
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if(dp[fr][1])
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que.push(Dt(fr,1));
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}
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}
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}
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else{
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int to=now.v;
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for(int i=0;i<rv[to].size();++i){
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int fr=rv[to][i];
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if(dp[fr][0]==0){
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dp[fr][0]=1;
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que.push(Dt(fr,0));
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}
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}
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}
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}
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int ans=1;
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for(int i=1;i<=n;++i){
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for(int j=i;j<=n;++j){
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ans&=dp[p2i[i][j]][0];
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}
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}
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if(ans) puts("YES");
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else puts("NO");
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}
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return 0;
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}
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