1 #include<iostream> 2 #include<cstdio> 3 #include<cstring> 4 using namespace std; 5 int t,n,m,head[205],next[2005],v[2005],cnt,dfn[205],cnt1,low[205]; 6 int zhan[205],zhan1[205],top,shu[205],shu1; 7 int du() 8 { 9 int a1; 10 char ch; 11 ch=getchar(); 12 for(;ch!='m'&&ch!='h';ch=getchar()); 13 scanf("%d",&a1); 14 if(ch=='m') 15 return a1*2; 16 else 17 return a1*2-1; 18 } 19 void jia(int a1,int a2) 20 { 21 cnt++; 22 next[cnt]=head[a1]; 23 head[a1]=cnt; 24 v[cnt]=a2; 25 return; 26 } 27 void dfs(int a1) 28 { 29 cnt1++; 30 low[a1]=dfn[a1]=cnt1; 31 zhan[a1]=1; 32 top++; 33 zhan1[top]=a1; 34 for(int i=head[a1];i;i=next[i]) 35 if(!dfn[v[i]]) 36 { 37 dfs(v[i]); 38 low[a1]=min(low[a1],low[v[i]]); 39 } 40 else 41 if(zhan[v[i]]) 42 low[a1]=min(low[a1],dfn[v[i]]); 43 if(low[a1]==dfn[a1]) 44 { 45 shu1++; 46 for(int i=zhan1[top];i!=a1;top--,i=zhan1[top]) 47 { 48 shu[i]=shu1; 49 zhan[i]=0; 50 } 51 top--; 52 shu[a1]=shu1; 53 zhan[a1]=0; 54 } 55 return; 56 } 57 int main() 58 { 59 scanf("%d",&t); 60 for(int i=0;i<t;i++) 61 { 62 memset(next,0,sizeof(next)); 63 shu1=0; 64 top=0; 65 cnt=0; 66 cnt1=0; 67 scanf("%d %d",&n,&m); 68 for(int i=1;i<=2*n;i++) 69 head[i]=dfn[i]=0; 70 for(int j=0;j<m;j++) 71 { 72 int a1,a2,b1,b2; 73 a1=du(); 74 b1=du(); 75 if(a1%2==0) 76 a2=a1-1; 77 else 78 a2=a1+1; 79 if(b1%2==0) 80 b2=b1-1; 81 else 82 b2=b1+1; 83 jia(a2,b1); 84 jia(b2,a1); 85 } 86 87 for(int i=1;i<=2*n;i++) 88 if(dfn[i]==0) 89 dfs(i); 90 int kg=1; 91 for(int i=1;i<=n;i++) 92 if(shu[i*2]==shu[i*2-1]) 93 { 94 kg=0; 95 printf("BAD "); 96 break; 97 } 98 if(kg) 99 printf("GOOD "); 100 } 101 return 0; 102 }
2-set问题，根据评委需求建边，比如h1，h2那m2向h1建边，m1向h2建边。求2-set时用tarjin找环。