2SAT
写挂again
1 #include<bits/stdc++.h> 2 using namespace std; 3 #define N 50010 4 #define M 100010 5 #define IL inline 6 #define RG register 7 #define INF (1<<30) 8 IL bool isitdigit(char c){ return c<='9'&&c>='0'; } 9 IL bool isitalpha(char c){ return c>='a'&&c<='z'; } 10 IL bool isitalphas(char c){ return c>='A'&&c<='Z'; } 11 IL int minify(int &a,int b){ return a<b? a:a=b; } 12 IL int read() 13 { 14 RG int s;RG char c; 15 while(!isitdigit(c=getchar())); 16 for(s=c-'0';isitdigit(c=getchar());s=(s<<1)+(s<<3)+c-'0'); 17 return s; 18 } 19 IL char readchar() 20 { 21 RG char c; 22 while(!isitalpha(c=getchar())); 23 return c; 24 } 25 IL char readchars() 26 { 27 RG char c; 28 while(!isitalphas(c=getchar())); 29 return c; 30 } 31 int n,m,d; 32 int color[M],trans[N],ord[N][5],another[M][4],anothertot,uncertain[10],uncertaintot,backup[M]; 33 int head[2][M],to[10*M],next[10*M],tot; 34 int inde,up[M],num[M]; 35 int st[M],top,belong[M],cnt,que[M],front,tail,du[M],vis[M]; 36 int opsite[M]; 37 IL void addedge(int d,int f,int t) 38 { 39 to[++tot]=t; 40 next[tot]=head[d][f]; 41 head[d][f]=tot; 42 } 43 void tarjan(int i) 44 { 45 up[i]=num[i]=++inde;st[++top]=i; 46 for(RG int j=head[0][i];j;j=next[j]) 47 if(!num[to[j]]) 48 { 49 tarjan(to[j]); 50 minify(up[i],up[to[j]]); 51 } 52 else if(!belong[to[j]]) 53 minify(up[i],num[to[j]]); 54 if(num[i]==up[i]) 55 { 56 cnt++; 57 for(;st[top]!=i;--top) belong[st[top]]=cnt; 58 belong[st[top]]=cnt; 59 top--; 60 } 61 } 62 IL bool judge() 63 { 64 for(RG int i=1;i<=n;++i) 65 if(belong[i]==belong[i+n]) return 1; 66 for(RG int i=1;i<=n+n;++i) 67 { 68 for(RG int j=head[0][i];j;j=next[j]) 69 if(belong[i]!=belong[to[j]]) 70 addedge(1,belong[i],belong[to[j]]),du[belong[to[j]]]++; 71 } 72 return 0; 73 } 74 IL void topsort() 75 { 76 memset(que,0,sizeof(que)); 77 tail=0;front=1; 78 for(RG int i=1;i<=cnt;++i) if(!du[i]) que[++tail]=i; 79 while(front<=tail) 80 { 81 int i=que[front++]; 82 for(RG int j=head[1][i];j;j=next[j]) 83 { 84 du[to[j]]--; 85 if(!du[to[j]]) que[++tail]=to[j]; 86 } 87 } 88 } 89 90 void dfs(int i) 91 { 92 vis[i]=-1; 93 for(RG int j=head[1][i];j;j=next[j]) 94 if(!vis[to[j]]) dfs(to[j]); 95 } 96 97 98 void print() 99 { 100 memset(opsite,0,sizeof(opsite)); 101 for(RG int i=1;i<=n;++i) opsite[belong[i]]=belong[i+n]; 102 for(RG int i=n;i<=n+n;++i) opsite[belong[i]]=belong[i-n]; 103 for(RG int i=1;i<=tail;i++) 104 { 105 if(!vis[que[i]]) 106 { 107 vis[que[i]]=1; 108 dfs(opsite[que[i]]); 109 } 110 } 111 for(RG int i=1;i<=n;++i) 112 printf("%c",vis[belong[i]]==1? color[i]:color[i+n]); 113 } 114 int main() 115 { 116 freopen("2sat.in","r",stdin); 117 n=read(),d=read(); 118 for(int ope=1;ope<=n;++ope) 119 { 120 RG char s=readchar(); 121 if(s=='x') 122 { 123 uncertain[++uncertaintot]=ope; 124 continue; 125 } 126 if(s=='a') 127 { 128 ord[ope]['B'-'A']=ope;color[ope]='B'; 129 ord[ope]['C'-'A']=ope+n;color[ope+n]='C'; 130 trans[ope]='B'+'C'-'A'; 131 } 132 else if(s=='b') 133 { 134 ord[ope]['A'-'A']=ope;color[ope]='A'; 135 ord[ope]['C'-'A']=ope+n;color[ope+n]='C'; 136 trans[ope]='A'+'C'-'A'; 137 } 138 else 139 { 140 ord[ope]['A'-'A']=ope;color[ope]='A'; 141 ord[ope]['B'-'A']=ope+n;color[ope+n]='B'; 142 trans[ope]='A'+'B'-'A'; 143 } 144 } 145 m=read(); 146 while(m--) 147 { 148 RG int i=read();RG char hi=readchars();RG int j=read();RG char hj=readchars(); 149 if(!trans[i]&&!trans[j]) 150 { 151 another[++anothertot][0]=i,another[anothertot][1]=hj,another[anothertot][2]=j,another[anothertot][3]=hj; 152 continue; 153 } 154 addedge(0,ord[j][hj-'A'],ord[i][hi-'A']); 155 addedge(0,ord[i][trans[i]-hi],ord[j][trans[j]-hj]); 156 } 157 for(int i=1;i<=n;++i) backup[i]=head[0][i],backup[i+n]=head[0][i+n]; 158 RG int still=tot+1; 159 for(RG int i=0;i<=(1<<uncertaintot)-1;++i) 160 { 161 memset(head[1],0,sizeof(head[1])); 162 memset(up,0,sizeof(up)); 163 memset(num,0,sizeof(num)); 164 memset(st,0,sizeof(st)); 165 memset(belong,0,sizeof(belong)); 166 memset(du,0,sizeof(du)); 167 memset(vis,0,sizeof(vis)); 168 cnt=top=inde=0; 169 for(RG int j=1;j<=n;++j) head[0][j]=backup[j],head[0][j+n]=backup[j+n]; 170 while(tot>=still) to[tot]=next[tot]=0,tot--; 171 for(RG int j=0;j<uncertaintot;++j) 172 if(i&(1<<j)) 173 { 174 ord[uncertain[j]]['B'-'A']=uncertain[j];color[uncertain[j]]='B'; 175 ord[uncertain[j]]['C'-'A']=uncertain[j]+n;color[uncertain[j]+n]='C'; 176 ord[uncertain[j]]['A'-'A']=0; 177 trans[uncertain[j]]='B'+'C'-'A'; 178 } 179 else 180 { 181 ord[uncertain[j]]['A'-'A']=uncertain[j];color[uncertain[j]]='A'; 182 ord[uncertain[j]]['B'-'A']=uncertain[j]+n;color[uncertain[j]+n]='B'; 183 ord[uncertain[j]]['C'-'A']=0; 184 trans[uncertain[j]]='A'+'B'-'A'; 185 } 186 for(RG int j=1;j<=anothertot;++j) 187 if(!ord[another[j][2]][another[j][3]-'A']&&ord[another[j][0]][another[j][1]-'A']) 188 addedge(0,ord[another[j][0]][trans[another[j][0]]-another[j][1]],ord[another[j][0]][another[j][1]-'A']); 189 else 190 { 191 addedge(0, ord[another[j][2]][another[j][3]-'A'],ord[another[j][0]][another[j][1]-'A']); 192 addedge(0,ord[another[j][0]][trans[another[j][0]]-another[j][1]],ord[another[j][2]][trans[another[j][2]]-another[j][3]]); 193 } 194 for(RG int j=1;j<=n+n;++j) if(!num[j]) tarjan(j); 195 if(judge()) continue; 196 topsort(); 197 print(); 198 return 0; 199 } 200 printf("-1"); 201 return 0; 202 }