UVALive 5135 Mining Your Own Business 双连通分量 2011final

  1 //struct ID 用来减小数字的，有点离散的作用。但是注释掉以后运行时间简短，AC
  2 #include<cstdio>
  3 #include<stack>
  4 #include<vector>
  5 #include<map>
  6 #include<algorithm>
  7 #include<cstring>
  8 using namespace std;
  9 typedef long long LL;
 10 
 11 struct Edge {
 12     int u, v;
 13 };
 14 
 15 const int maxn = 100000 + 10;
 16 int pre[maxn], iscut[maxn], bccno[maxn], dfs_clock, bcc_cnt; // 割顶的bccno无意义
 17 vector<int> G[maxn], bcc[maxn];
 18 
 19 stack<Edge> S;
 20 
 21 int dfs(int u, int fa) {
 22     int lowu = pre[u] = ++dfs_clock;
 23     int child = 0;
 24     for(int i = 0; i < G[u].size(); i++) {
 25         int v = G[u][i];
 26         Edge e = (Edge) {
 27             u, v
 28         };
 29         if(!pre[v]) { // 没有访问过v
 30             S.push(e);
 31             child++;
 32             int lowv = dfs(v, u);
 33             lowu = min(lowu, lowv); // 用后代的low函数更新自己
 34             if(lowv >= pre[u]) {
 35                 iscut[u] = true;
 36                 bcc_cnt++;
 37                 bcc[bcc_cnt].clear();
 38                 for(;;) {
 39                     Edge x = S.top();
 40                     S.pop();
 41                     if(bccno[x.u] != bcc_cnt) {
 42                         bcc[bcc_cnt].push_back(x.u);
 43                         bccno[x.u] = bcc_cnt;
 44                     }
 45                     if(bccno[x.v] != bcc_cnt) {
 46                         bcc[bcc_cnt].push_back(x.v);
 47                         bccno[x.v] = bcc_cnt;
 48                     }
 49                     if(x.u == u && x.v == v) break;
 50                 }
 51             }
 52         } else if(pre[v] < pre[u] && v != fa) {
 53             S.push(e);
 54             lowu = min(lowu, pre[v]); // 用反向边更新自己
 55         }
 56     }
 57     if(fa < 0 && child == 1) iscut[u] = 0;
 58     return lowu;
 59 }
 60 
 61 //struct ID {
 62 //    map<int, int> m;
 63 //    int cnt;
 64 //    ID():cnt(0) { }
 65 //    int get(int x) {
 66 //        if(!m.count(x)) m[x] = cnt++;
 67 //        return m[x];
 68 //    }
 69 //};
 70 
 71 int main() {
 72     int kase = 0, n;
 73     while(scanf("%d", &n) == 1 && n) {
 74         memset(pre, 0, sizeof(pre));
 75         memset(iscut, 0, sizeof(iscut));
 76         memset(bccno, 0, sizeof(bccno));
 77         for(int i = 0; i < n*2; i++) G[i].clear();
 78         dfs_clock = bcc_cnt = 0;
 79 
 80 //        ID id;
 81         for(int i = 0; i < n; i++) {
 82             int u, v;
 83             scanf("%d%d", &u, &v);
 84 //            u = id.get(u);
 85 //            v = id.get(v);
 86             u--;
 87             v--;
 88             G[u].push_back(v);
 89             G[v].push_back(u);
 90         }
 91         dfs(0, -1); // 调用结束后S保证为空，所以不用清空
 92 
 93         LL ans1 = 0, ans2 = 1;
 94         for(int i = 1; i <= bcc_cnt; i++) {
 95             int cut_cnt = 0;
 96             for(int j = 0; j < bcc[i].size(); j++)
 97                 if(iscut[bcc[i][j]]) cut_cnt++;
 98             if(cut_cnt == 1) {
 99                 ans1++;
100                 ans2 *= (LL)(bcc[i].size() - cut_cnt);
101             }
102         }
103         if(bcc_cnt == 1) {
104             ans1 = 2;
105             ans2 = bcc[1].size() * (bcc[1].size() - 1) / 2;
106         }
107         printf("Case %d: %lld %lld\n", ++kase, ans1, ans2);
108     }
109     return 0;
110 }