【POJ】【3710】Christmas Game

博弈论

　　贾志豪论文上的题目……题解请看论文

　　Orz了一下Hzwer

 Source Code
 Problem:         User: sdfzyhy
 Memory: 716K        Time: 0MS
 Language: G++        Result: Accepted

     Source Code

     //POJ 3710
     #include<cstdio>
     #include<cstring>
     #include<iostream>
     #define F(i,j,n) for(int i=j;i<=n;++i)
     int getint(){
         int v=,sign=; char ch=getchar();
         while(!isdigit(ch)) {if(ch=='-') sign=-; ch=getchar();}
         while(isdigit(ch))  {v=v*+ch-''; ch=getchar();}
         return v*sign;
     }
     const int N=,INF=~0u>>;
     const double eps=1e-;
     /*******************template********************/
     int to[N],next[N],head[N],cnt,s[N],top;
     bool vis[N],ve[N],w[N];
     void add(int x,int y){
         to[++cnt]=y; next[cnt]=head[x]; head[x]=cnt;
         to[++cnt]=x; next[cnt]=head[y]; head[y]=cnt;
     }
     int dfs(int x){
         vis[x]=;
         int ans=;
         s[++top]=x;
         for(int i=head[x];i;i=next[i])
             if(!ve[i]){
                 ve[i]=ve[i^]=;
                 int temp;
                 if (!vis[to[i]]) temp=dfs(to[i])+;
                 else{
                 int q=s[top--];
                 while(q!=to[i]){
                         w[q]=;//环上节点标记
                         q=s[top--];
                     }
                     ++top;
                     return ;
                 }//缩环
                 if(w[to[i]]) ans^=temp%;
                 else ans^=temp;
             }
         return ans;
     }
     void clear(){
         memset(head,,sizeof head);
         memset(next,,sizeof next);
         memset(vis,,sizeof vis);
         memset(ve,,sizeof ve);
         memset(w,,sizeof w);
         top=; cnt=;
     }
     int main(){
         int T,n,m,x,y;
         while(scanf("%d",&T)!=EOF){
             int ans=;
             F(i,,T){
                 clear();
                 n=getint(); m=getint();
                 F(i,,m){
                     x=getint(); y=getint();
                     add(x,y);
                 }
                 ans^=dfs();
             }
             puts(ans ? "Sally" : "Harry");
         }
         return ;
     }