Let's go home

 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        else
93         printf("no\n");
94    }
95 
96 }