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[305][305], n, m, k;
const int INF = 0x3f3f3f3f;
int main()
{
    memset(a, 0x3f, sizeof(a));
    cin >> n >> m;
    for (int i = 0; i < m; i++)
    {
        vector<int> l;
        int tmp;
        cin >> k;
        for (int j = 0; j < k; j++)
        {
            cin >> tmp;
            l.push_back(tmp);
        }
        for (int p = 0; p < k; p++)
        {
            for (int q = 0; q < k; q++)
            {
                a[l[p]][l[q]] = p == q ? 0 : 1;
            }
        }
    }
    for (int k = 1; k <= n; k++)
    {
        for (int i = 1; i <= n; i++)
        {
            for (int j = 1; 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 = 1; j <= n; j++)
    {
        int sum = 0;
        for (int k = 1; k <= n; k++)
        {
            sum += a[j][k];
        }
        double ans = sum * 1.0 / (n - 1);
        __ = min(ans, __);
    }
    cout << (int)(__ * 100) << endl;
    return 0;
}