哦哦

#include < iostream >
#define  maxn 51
using   namespace  std;
int  map[maxn][maxn];
int  lx[maxn],ly[maxn],slack[maxn];
bool  vx[maxn],vy[maxn];
int  cas,n,m;
int  match[maxn];
int  ans;
int  dfs( int  t)
{
     int  i;
    vx[t] = 1 ;
     int  tmp;
     for (i = 1 ;i <= n;i ++ )
    {
         if ( ! vy[i])
        {
             tmp = lx[t] + ly[i] - map[t][i];
              if (tmp == 0 )
             {
                    vy[i] = 1 ;
                     if (match[i] ==- 1 || dfs(match[i]))
                    {
                        match[i] = t;
                         return   1 ;
                    }
             }
              else   if (slack[i] > tmp)
                     slack[i] = tmp;
        }
    }
     return   0 ;
}
int  KM()
{
     int  i,j;
    memset(match, - 1 , sizeof (match));
     for (i = 1 ;i <= n;i ++ )
    {
        lx[i] =- 10000000 ;
         for (j = 1 ;j <= n;j ++ )
        {
             if (lx[i] < map[i][j])
                lx[i] = map[i][j];
        }
    }
    memset(ly, 0 , sizeof (ly));    
     for (i = 1 ;i <= n;i ++ )
    {
        memset(slack, 0x3f , sizeof (slack));
         while ( 1 )
        {
            memset(vx, 0 , sizeof (vx));
            memset(vy, 0 , sizeof (vy));
             if (dfs(i))
                 break ;
             int  d = 10000000 ;
             for (j = 1 ;j <= n;j ++ )
                 if ( ! vy[j] && d > slack[j])
                    d = slack[j];          
             for (j = 1 ;j <= n;j ++ )  
            {  
                 if (vx[j]) 
                    lx[j] -= d; 
                  if (vy[j]) 
                     ly[j] += d;  
            }          
        }
    }
     for (i = 1 ;i <= n;i ++ )
    {
         if (match[i] !=- 1 )
            ans += map[match[i]][i];
    }
     return   0 ;
}