1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 #include<algorithm> 5 using namespace std; 6 int t,m,n; 7 const int N=200010; 8 const int M=400010; 9 const int INF=0xffffffff;10 struct Edge{11     int to,next;12 } edge[M];13 int  cnt,u,v,dep,top,atype;14 int  dfn[N],low[N],vis[N],head[N],st[N],belong[N],in[N],out[N],sum[N];15 //sum[i]记录第i个连通图的点的个数,in[i],out[i],表示缩点之后点的入度和初度。16 void init(){17       cnt=dep=top=atype=0;18     memset(head,-1,sizeof(head));19     memset(dfn,0,sizeof(dfn));20     memset(low,0,sizeof(low));21     memset(vis,0,sizeof(vis));22     memset(belong,0,sizeof(belong));23     memset(in,0,sizeof(in));24     memset(out,0,sizeof(out));25     memset(sum,0,sizeof(sum));26 }27 void addedge(int u,int v){28     edge[cnt].to=v;29     edge[cnt].next=head[u];30     head[u]=cnt++;31 }32 33 void Tarjan(int u){34     dfn[u]=low[u]=++dep;35     st[top++]=u;36     vis[u]=1;37     for(int i=head[u]; i!=-1; i=edge[i].next){38         int v=edge[i].to;39         if(!dfn[v]){40             Tarjan(v);41             low[u]=min(low[u],low[v]);42         }43         else if(vis[v]){44             low[u]=min(low[u],dfn[v]);45         }46     }47     int j;48     if(dfn[u]==low[u]){49         atype++;50         do{51             j=st[--top];52             belong[j]=atype;53             sum[atype]++;   //记录每个连通分量中点的个数54             vis[j]=0;55         }56         while(u!=j);57     }58 }59 int fg[N],t1,t2,t3;60 int main(){61    while(~scanf("%d%d",&t,&m)){62       int a,b,c;63     int base=3*t;64     init();65     for(int i=0;i<t;i++){66         scanf("%d%d%d",&a,&b,&c);67          addedge(b,c);68          addedge(c,b);69          addedge(b+base,c+base);70          addedge(c+base,b+base);71          addedge(a+base,b);72          addedge(a+base,c);73          addedge(b+base,a);74          addedge(c+base,a);75     }76     while(m--){77         scanf("%d%d",&a,&b);78          addedge(a,b+base);79          addedge(b,a+base);80     }81       for(int i=0; i<6*t; i++)82         if(!dfn[i])83             Tarjan(i);84        bool flag=false;85        for(int i=1;i<3*t;i++){86          if(belong[i]==belong[i+base]){87             flag=true;88            break;89          }90        }91        if(!flag)printf("yes\n");92        else93         printf("no\n");94    }95 96 }