学步园

思路：转化为二分图，求最大匹配。但如何构图呢？？？
把n门课看成是x中的点集，上课时间为y中的点集 （p-1）*12 + q 当作点 
然后就是模板了，不多说了

#include <stdio.h>
#include <string.h>
#define M 305
#define N 100
int map[M][N];
int link[N],vis[N];
int n,m;

int DFS(int u)
{
    int v;
    for (v = 1;v
<= m;v ++)
       
if (!vis[v]&&map[u][v])
       
{
           
vis[v] = 1;
           
if (link[v] == -1||DFS(link[v]))
           
{
               
link[v] = u;
               
return 1;
           
}
       
}
    return
0;
}
int MaxMatch ()
{
    int u,res =
0;
    memset
(link,-1,sizeof(link));
    for (u = 1;u
<= n;u ++)
    {
       
memset (vis,0,sizeof(vis));
       
if (DFS(u))
           
res ++;
    }
    return
res;
}
int main ()
{
    int
t,p,q;
    while
(~scanf ("%d",&n))
    {
       
memset (map,0,sizeof(map));
       
m = 0;
       
for (int i = 1;i <= n;i ++)
       
{
           
scanf ("%d",&t);
           
while (t --)
           
{
               
scanf ("%d%d",&p,&q);
               
m = m > (p-1)*12 + q?m:((p-1)*12+q);