HDU 4685 Prince and Princess

  1 #include <iostream>
  2 #include <cstdio>
  3 #include <cstring>
  4 #include <cmath>
  5 #include <algorithm>
  6 #include <climits>
  7 #include <vector>
  8 #include <queue>
  9 #include <cstdlib>
 10 #include <string>
 11 #include <set>
 12 #include <stack>
 13 #define LL long long
 14 #define pii pair<int,int>
 15 #define INF 0x3f3f3f3f
 16 using namespace std;
 17 const int maxn = 50000;
 18 struct arc {
 19     int to,next;
 20     arc(int x = 0,int y = -1) {
 21         to = x;
 22         next = y;
 23     }
 24 };
 25 arc e[500000];
 26 int head[maxn],dfn[maxn],low[maxn],belong[maxn];
 27 int tot,nx,ny,top,scc,idx,lx[maxn],ly[maxn],mystack[maxn];
 28 bool mp[1000][1000],instack[maxn],vis[maxn];
 29 void add(int u,int v) {
 30     e[tot] = arc(v,head[u]);
 31     head[u] = tot++;
 32 }
 33 bool dfs(int u) {
 34     for(int i = 1; i <= ny; ++i) {
 35         if(mp[u][i]&&!vis[i]) {
 36             vis[i] = true;
 37             if(ly[i] == -1 || dfs(ly[i])) {
 38                 ly[i] = u;
 39                 lx[u] = i;
 40                 return true;
 41             }
 42         }
 43     }
 44     return false;
 45 }
 46 int hungry() {
 47     memset(lx,-1,sizeof(lx));
 48     memset(ly,-1,sizeof(ly));
 49     int ans = 0;
 50     for(int i = 1; i <= nx; ++i) {
 51         memset(vis,false,sizeof(vis));
 52         ans += dfs(i);
 53     }
 54     return ans;
 55 }
 56 void tarjan(int u) {
 57     dfn[u] = low[u] = ++idx;
 58     instack[u] = true;
 59     mystack[top++] = u;
 60     for(int i = head[u]; ~i; i = e[i].next) {
 61         if(!dfn[e[i].to]) {
 62             tarjan(e[i].to);
 63             low[u] = min(low[u],low[e[i].to]);
 64         } else if(instack[e[i].to]) low[u] = min(low[u],dfn[e[i].to]);
 65     }
 66     if(dfn[u] == low[u]) {
 67         int v;
 68         scc++;
 69         do {
 70             v = mystack[--top];
 71             instack[v] = false;
 72             belong[v] = scc;
 73         } while(v != u);
 74     }
 75 }
 76 void init() {
 77     for(int i = 0; i < maxn; ++i) {
 78         dfn[i] = low[i] = belong[i] = 0;
 79         instack[i] = false;
 80         head[i] = -1;
 81     }
 82     tot = scc = idx = top = 0;
 83     memset(mp,false,sizeof(mp));
 84 }
 85 int main() {
 86     int T,cs = 1,n,m,k,u,v;
 87     scanf("%d",&T);
 88     while(T--) {
 89         scanf("%d %d",&n,&m);
 90         nx = n;
 91         ny = m;
 92         init();
 93         for(int i = 1; i <= n; ++i) {
 94             scanf("%d",&k);
 95             while(k--) {
 96                 scanf("%d",&v);
 97                 mp[i][v] = true;
 98             }
 99         }
100         nx = ny = n + m - hungry();
101         for(int i = n+1; i <= nx; ++i)
102             for(int j = 1; j <= ny; ++j)
103                 mp[i][j] = true;//建立虚拟王子
104         for(int i = m+1; i <= ny; ++i)
105             for(int j = 1; j <= nx; ++j)
106                 mp[j][i] = true;//建立虚拟公主
107         hungry();
108         for(int i = 1; i <= nx; ++i) {
109             for(int j = 1; j <= ny; ++j)
110                 if(mp[i][j] && lx[i] != j)  add(lx[i],j);
111         }
112         for(int i = 1; i <= nx; ++i)
113             if(!dfn[i]) tarjan(i);
114         printf("Case #%d:\n",cs++);
115         vector<int>ans;
116         for(int i = 1; i <= n; ++i) {
117             ans.clear();
118             for(int j = m; j >= 0; --j)
119                 if(mp[i][j]&& belong[lx[i]] == belong[j]) ans.push_back(j);
120             printf("%d",ans.size());
121             for(int j = ans.size()-1; j >= 0; --j)
122                 printf(" %d",ans[j]);
123             putchar(‘\n‘);
124         }
125     }
126     return 0;
127 }