mirror of
https://github.com/Kiritow/OJ-Problems-Source.git
synced 2024-03-22 13:11:29 +08:00
219 lines
6.0 KiB
C++
219 lines
6.0 KiB
C++
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#include<stdio.h>
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#include<iostream>
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#include<algorithm>
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#include<iostream>
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using namespace std;
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const int MAXN=16010;
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const int MAXM=100000;
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struct Node
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{
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int a,b,pre,next;
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}E[MAXM],E2[MAXM];
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int _n,n,m;
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int V[MAXN],ST[MAXN][2],Q[MAXN],Q2[MAXN],vst[MAXN];
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bool res_ex;
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void init_d()
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{
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for(int i=0;i<n;i++)
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E[i].a=E[i].pre=E[i].next=E2[i].a=E2[i].pre=E2[i].next=i;
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m=n;
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}
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void add_edge(int a,int b)
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{
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E[m].a=a;E[m].b=b;E[m].pre=E[a].pre;E[m].next=a;E[a].pre=m;E[E[m].pre].next=m;
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E2[m].a=b;E2[m].b=a;E2[m].pre=E2[b].pre;E2[m].next=b;E2[b].pre=m;E2[E2[m].pre].next=m;
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m++;
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}
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void solve()
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{
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for(int i=0;i<n;i++)
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{
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V[i]=0;
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vst[i]=0;
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}
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res_ex=1;
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int i,i1,i2,j,k,front,rear,front2,rear2;
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int len;
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bool ff;
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for(int _i=0;_i<_n;_i++)
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{
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if(V[_i<<1]==1||V[(_i<<1)+1]==1)continue;
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i=_i<<1;len=0;
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if(!V[i])
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{
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ST[len][0]=i;
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ST[len++][1]=1;
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if(!V[i^1])
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{
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ST[len][0]=i^1;
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ST[len++][1]=2;
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}
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Q[front=rear=0]=i;
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vst[i]=i1=n+i;
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Q2[front2=rear2=0]=i^1;
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vst[i^1]=i2=(n<<1)+i;
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ff=1;
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for(;front<=rear;front++)
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{
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j=Q[front];
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for(int p=E[j].next;p!=j;p=E[p].next)
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{
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k=E[p].b;
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if(V[k]==2||vst[k]==i2||V[k^1]==1||vst[k^1]==i1)
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{ff=0;break;}
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if(vst[k]!=i1)
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{
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Q[++rear]=k;vst[k]=i1;
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if(!V[k])
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{
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ST[len][0]=k;
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ST[len++][1]=1;
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}
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}
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if(vst[k^1]!=i2)
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{
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Q2[++rear2]=k^1;vst[k^1]=i2;
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if(!V[k])
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{
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ST[len][0]=k^1;
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ST[len++][1]=2;
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}
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}
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}
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if(!ff)break;
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}
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if(ff)
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{
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for(;front2<=rear2;front2++)
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{
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j=Q2[front2];
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for(int p=E2[j].next;p!=j;p=E2[p].next)
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{
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k=E2[p].b;
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if(V[k]==1||vst[k]==i1)
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{ff=0;break;}
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if(vst[k]!=i2)
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{
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vst[k]=i2;Q2[++rear]=k;
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if(!V[k])
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{
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ST[len][0]=k;
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ST[len++][1]=2;
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}
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}
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}
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if(!ff)break;
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}
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if(ff)
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{
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for(int j=0;j<len;j++)V[ST[j][0]]=ST[j][1];
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continue;
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}
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}
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}
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i=(_i<<1)+1;len=0;
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if(!V[i])
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{
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ST[len][0]=i;
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ST[len++][1]=1;
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if(!V[i^1])
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{
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ST[len][0]=i^1;
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ST[len++][1]=2;
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}
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Q[front=rear=0]=i;
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vst[i]=i1=n+i;
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Q2[front2=rear2=0]=i^1;
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vst[i^1]=i2=(n<<1)+i;
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ff=1;
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for(;front<=rear;front++)
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{
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j=Q[front];
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for(int p=E[j].next;p!=j;p=E[p].next)
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{
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k=E[p].b;
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if(V[k]==2||vst[k]==i2||V[k^1]==1||vst[k^1]==i1)
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{ff=0;break;}
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if(vst[k]!=i1)
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{
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Q[++rear]=k;vst[k]=i1;
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if(!V[k])
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{
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ST[len][0]=k;
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ST[len++][1]=1;
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}
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}
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if(vst[k^1]!=i2)
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{
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Q2[++rear2]=k^1;vst[k^1]=i2;
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if(!V[k])
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{
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ST[len][0]=k^1;
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ST[len++][1]=2;
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}
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}
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}
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if(!ff)break;
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}
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if(ff)
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{
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for(;front2<=rear2;front2++)
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{
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j=Q2[front2];
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for(int p=E2[j].next;p!=j;p=E2[p].next)
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{
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k=E2[p].b;
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if(V[k]==1||vst[k]==i1)
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{ff=0;break;}
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if(vst[k]!=i2)
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{
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vst[k]=i2;Q2[++rear]=k;
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if(!V[k])
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{
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ST[len][0]=k;
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ST[len++][1]=2;
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}
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}
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}
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if(!ff)break;
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}
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if(ff)
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{
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for(int j=0;j<len;j++)V[ST[j][0]]=ST[j][1];
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continue;
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}
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}
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}
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if(V[_i<<1]+V[(_i<<1)+1]!=3){res_ex=0;break;}
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}
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}
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int main()
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{
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int M;
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int x,y;
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while(scanf("%d%d",&_n,&M)!=EOF)
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{
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n=_n<<1;
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init_d();
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while(M--)
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{
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scanf("%d%d",&x,&y);
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x--;
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y--;
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if(x!=(y^1))
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{
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add_edge(x,y^1);
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add_edge(y,x^1);
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}
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}
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solve();
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if(res_ex)
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{
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for(int i=0;i<n;i++)
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if(V[i]==1)printf("%d\n",i+1);
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}
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else printf("NIE\n");
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}
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return 0;
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}
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