poj2139 Six Degrees of Cowvin Bacon

思路：

floyd

实现：

 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <vector>
 #include <algorithm>
 using namespace std;

 int a[][], n, m, k;
 const int INF = 0x3f3f3f3f;
 int main()
 {
     memset(a, 0x3f, sizeof(a));
     cin >> n >> m;
     for (int i = ; i < m; i++)
     {
         vector<int> l;
         int tmp;
         cin >> k;
         for (int j = ; j < k; j++)
         {
             cin >> tmp;
             l.push_back(tmp);
         }
         for (int p = ; p < k; p++)
         {
             for (int q = ; q < k; q++)
             {
                 a[l[p]][l[q]] = p == q ?  : ;
             }
         }
     }
     for (int k = ; k <= n; k++)
     {
         for (int i = ; i <= n; i++)
         {
             for (int j = ; j <= n; j++)
             {
                 if (a[i][k] + a[k][j] < a[i][j])
                 {
                     a[i][j] = a[i][k] + a[k][j];
                 }
             }
         }
     }
     double __ = INF;
     for (int j = ; j <= n; j++)
     {
         int sum = ;
         for (int k = ; k <= n; k++)
         {
             sum += a[j][k];
         }
         double ans = sum * 1.0 / (n - );
         __ = min(ans, __);
     }
     cout << (int)(__ * ) << endl;
     return ;
 }