112 lines
2.2 KiB
C++
112 lines
2.2 KiB
C++
#include<iostream>
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#include<algorithm>
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#include<string.h>
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using namespace std;
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int f[20010],r[20010],n;
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int map[20010];
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int xp[20],ans;
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void init()
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{
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for(int i=0;i<=n;i++)
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{
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f[i]=i;
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r[i]=0;
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}
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}
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int find(int x)
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{
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if(x==f[x])
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return x;
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int t=find(f[x]);
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r[x]^=r[f[x]];//规x涓惰圭崇郴姹x涓硅圭崇郴
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f[x]=t;
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return f[x];
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}
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bool Union(int x,int y,int k)
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{
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int a=find(x);
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int b=find(y);
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if(a==b)
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{
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if((r[x]^r[y])==k)
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return true;
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return false;
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}
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if(a==n)
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swap(a,b);
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f[a]=b;
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r[a]=r[x]^r[y]^k;
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return true;
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}
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bool query(int m)
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{
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memset(map,0,sizeof(map));
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for(int i=0;i<m;i++)
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{
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map[find(xp[i])]++;
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ans^=r[xp[i]];
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}
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int flag=0;
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for(int i=0;i<m;i++)
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{
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int t=find(xp[i]);
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if(map[t]%2!=0 && t!=n)
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{flag=1;break;}
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}
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if(flag)
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return false;
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return true;
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}
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int main()
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{
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char s[2],c;
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int a,b,v,Q,cas=0;
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while(scanf("%d %d",&n,&Q)==2 &&(n||Q))
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{
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init();
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printf("Case %d:\n",++cas);
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int fact=0,flag=0;
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while(Q--)
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{
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scanf("%s%d%d",s,&a,&b);
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if(s[0]=='I')
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{
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fact++;
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c=getchar();
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if(c==' ')
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{
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scanf("%d",&v);
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if(flag)continue;
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if(!Union(a,b,v))
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{
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printf("The first %d facts are conflicting.\n",fact);
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flag=1;
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}
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}
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else
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{
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if(flag)continue;
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if(!Union(a,n,b))
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{
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printf("The first %d facts are conflicting.\n",fact);
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flag=1;
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}
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}
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}
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else
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{
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xp[0]=b;
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for(int i=1;i<a;i++)
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scanf("%d",&xp[i]);
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if(flag)continue;
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ans=0;
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if(query(a))
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printf("%d\n",ans);
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else printf("I don't know.\n");
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}
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}
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printf("\n");
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}
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return 0;
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}
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