2014西安 H 有向图博弈 UVALive-7042

  1 #include <bits/stdc++.h>
  2 #define maxn 110
  3 #define inf 0x3f3f3f3f
  4 #define REP(i,x,y) for(int i=x;i<(y);i++)
  5 #define RREP(i,x,y) for(int i=x;i>(y);i--)
  6 using namespace std;
  7 typedef long long ll;
  8 typedef pair<int,int>pii;
  9 int n,m;
 10 vector<int>e[maxn];
 11 int cnt[maxn][maxn][2],dp[maxn][maxn][2],vis[maxn][maxn][2],out[maxn];
 12 struct P{
 13     int pos_b,pos_a,op;
 14     P(){}
 15     P(int _,int __,int ___):pos_b(_),pos_a(__),op(___){}
 16 };
 17 int main()
 18 {
 19     int T,cas=1;scanf("%d",&T);
 20     while(T--) {
 21         queue<P>que;
 22         scanf("%d %d",&n,&m);
 23         for(int i=1;i<=n;i++) {
 24             out[i]=0;
 25             for(int j=1;j<=n;j++) {
 26                 dp[i][j][0]=dp[i][j][1]=-1;
 27                 vis[i][j][0]=vis[i][j][1]=0;
 28             }
 29             e[i].clear();
 30         }
 31         REP(i,1,m+1) {
 32             int u,v;scanf("%d %d",&u,&v);
 33             e[v].push_back(u);
 34             out[u]++;
 35         }
 36         REP(i,1,n+1) {vis[i][i][0]=1;dp[i][i][0]=0,que.push(P(i,i,0));}
 37         REP(i,1,n+1) {vis[i][i][1]=1;dp[i][i][1]=1,que.push(P(i,i,1));}
 38         REP(op,0,2) {       //0 Bob 1 Alice
 39             REP(i,1,n+1) {
 40                 REP(j,1,n+1) {
 41                     if(i==j) continue;
 42                     if(op==0) {
 43                         if(out[i]==0) {
 44                             dp[i][j][op]=0,que.push(P(i,j,op));
 45                             vis[i][j][op]=1;
 46                         }
 47                        // else if(out[i]==1&&pre[i][0]==j) dp[i][j][op]=0,que.push(P(i,j,op));
 48                     }
 49                     else {
 50                         if(out[j]==0) {
 51                             dp[i][j][op]=0,que.push(P(i,j,op));
 52                             vis[i][j][op]=1;
 53                         }
 54                     }
 55                 }
 56             }
 57         }
 58         REP(i,1,n+1) REP(j,1,n+1) cnt[i][j][0]=out[i];
 59         REP(i,1,n+1) REP(j,1,n+1) cnt[i][j][1]=out[j];
 60         while(!que.empty()) {
 61             P now=que.front();que.pop();
 62 
 63             int v1=now.pos_b,v2=now.pos_a;
 64             // cout << v1 <<" "<< v2 <<" " << now.op  <<" "<<dp[v1][v2][now.op]<< endl;
 65            // cout<<v1<<" "<<v2<<" "<<now.op<<endl;
 66             if(!now.op) {       //bob
 67                 int Size=e[v2].size();
 68                 REP(i,0,Size) {
 69                     if(dp[v1][v2][now.op]==0) {
 70                         if(vis[v1][e[v2][i]][1]) continue;
 71                         dp[v1][e[v2][i]][1]=1;
 72                         vis[v1][e[v2][i]][1]=1;
 73                         que.push(P(v1,e[v2][i],1));
 74                     }
 75                     else if(dp[v1][v2][now.op]) {
 76                         if(vis[v1][e[v2][i]][1]) continue;
 77                         cnt[v1][e[v2][i]][1]--;
 78                         if(cnt[v1][e[v2][i]][1]==0) {
 79                             dp[v1][e[v2][i]][1]=0;
 80                             que.push(P(v1,e[v2][i],1));
 81                             vis[v1][e[v2][i]][1]=1;
 82                         }
 83                     }
 84                 }
 85             }
 86             else {          //Alice
 87                 int Size=e[v1].size();
 88                // cout<<Size<<endl;
 89                 REP(i,0,Size) {
 90                     if(dp[v1][v2][now.op]==0) {
 91                         if(vis[e[v1][i]][v2][0]) continue;
 92                         dp[e[v1][i]][v2][0]=1;
 93                         vis[e[v1][i]][v2][0]=1;
 94                         que.push(P(e[v1][i],v2,0));
 95                     }
 96                     else if(dp[v1][v2][now.op]) {
 97                         if(vis[e[v1][i]][v2][0]) continue;
 98                         cnt[e[v1][i]][v2][0]--;
 99                         if(cnt[e[v1][i]][v2][0]==0) {
100                             dp[e[v1][i]][v2][0]=0;
101                             que.push(P(e[v1][i],v2,0));
102                             vis[e[v1][i]][v2][0]=1;
103                         }
104                     }
105                 }
106             }
107         }
108         int x,y;scanf("%d %d",&x,&y);
109         printf("Case #%d: ",cas++);
110         //cout<<dp[x][y][0]<<endl;
111         if(dp[x][y][0]) puts("Yes");
112         else puts("No");
113     }
114 }