POJ 3710

  1 #include <iostream>
  2 #include <cstdio>
  3 #include <cstring>
  4 
  5 
  6 using namespace std;
  7 
  8 const int N=110;
  9 const int M=1100;
 10 int n,m;
 11 struct {
 12     int v,next;
 13 }edge[M];
 14 struct {
 15     int u,v;
 16 }edge_stack[M],tmp;
 17 int dfn[N],low[N],index;
 18 int edge_top,tot;
 19 bool vis[N],vis_e[M];
 20 int head[N],sg[N];
 21 
 22 void addedge(int u,int v){
 23     vis_e[tot]=false;
 24     edge[tot].v=v;
 25     edge[tot].next=head[u];
 26     head[u]=tot++;
 27 }
 28 
 29 void tarjan(int u){
 30     int i,j,k,v,e;
 31     dfn[u]=low[u]=++index;
 32     for(e=head[u];e!=-1;e=edge[e].next){
 33         v=edge[e].v;
 34         if(dfn[v]==-1){
 35             vis_e[e]=vis_e[e^1]=true;
 36             edge_stack[++edge_top].u=u;
 37             edge_stack[edge_top].v=v;
 38             tarjan(v);
 39             low[u]=min(low[u],low[v]);
 40             if(dfn[u]<=low[v]){
 41                 int cnt=0;
 42                 do{
 43                     tmp.u=edge_stack[edge_top].u;
 44                     tmp.v=edge_stack[edge_top].v;
 45                     edge_top--;
 46                     cnt++;
 47                     vis[tmp.u]=vis[tmp.v]=true;
 48                 //    printf("edge=%d %d ",tmp.u,tmp.v);
 49                 }while(!(tmp.u==u&&tmp.v==v));
 50             //    printf("\n");
 51                 if((cnt&1)){
 52                     vis[tmp.u]=vis[tmp.v]=false;
 53                 }
 54                 else vis[tmp.u]=false;
 55             }
 56         }
 57         else{
 58             if(!vis_e[e]){
 59                 low[u]=min(low[u],dfn[v]);
 60                 if(dfn[u]>dfn[v]){
 61                     edge_stack[++edge_top].u=u;
 62                     edge_stack[edge_top].v=v;
 63                 }
 64             }
 65         }
 66     }
 67 }
 68 
 69 int dfs(int u){
 70     int e,v;
 71     vis[u]=true;
 72     int ans=sg[u];
 73     for(e=head[u];e!=-1;e=edge[e].next){
 74         int v=edge[e].v;
 75         if(!vis[v]){
 76             ans^=(dfs(v)+1);
 77         }
 78     }
 79     return ans;
 80 }
 81 
 82 int main(){
 83     int k,u,v;
 84     while(scanf("%d",&k)!=EOF){
 85         int ans=0;
 86         while(k--){
 87         edge_top=-1;
 88         scanf("%d%d",&n,&m);
 89         tot=index=0;
 90         for(int i=1;i<=n;i++){
 91             vis[i]=false; sg[i]=0;
 92             head[i]=dfn[i]=low[i]=-1;
 93         }
 94         for(int i=1;i<=m;i++){
 95             scanf("%d%d",&u,&v);
 96             addedge(u,v);
 97             addedge(v,u);
 98         }
 99         tarjan(1);
100         ans^=dfs(1);
101         }
102         if(ans) printf("Sally\n");
103         else printf("Harry\n");
104     }
105     return 0;
106 }