hdu1281 棋盘游戏

 1 #include <iostream>
 2 #include <string.h>
 3 using namespace std;
 4 #define MAXN 105
 5 int uN,vN;//u,v数目
 6 int map[MAXN][MAXN];
 7 int linker[MAXN];
 8 bool used[MAXN];
 9 int x[MAXN],y[MAXN];
10 bool dfs(int u)//从左边开始找增广路径
11 {
12     int v;
13     for(v=1;v<=vN;v++)//这个顶点编号从0开始，若要从1开始需要修改
14         if(map[u][v]&&!used[v])
15         {
16             used[v]=true;
17             if(linker[v]==-1||dfs(linker[v]))
18             {//找增广路，反向
19                 linker[v]=u;
20                 return true;
21             }
22         }
23         return false;//这个不要忘了，经常忘记这句
24 }
25 int hungary()
26 {
27     int res=0;
28     int u;
29     memset(linker,-1,sizeof(linker));
30     for(u=1;u<=uN;u++)
31     {
32         memset(used,0,sizeof(used));
33         if(dfs(u)) res++;
34     }
35     return res;
36 }
37 int main()
38 {
39     int k,a,b,count,ans,res;
40     int t = 1;
41     //freopen("1281.txt","r",stdin);
42     while(~scanf("%d %d %d",&uN,&vN,&k))
43     {
44         count = 0;
45         memset(map,0,sizeof(map));
46         for(int i = 0; i  < k ; i++)
47         {
48             scanf("%d %d",&a,&b);
49             map[a][b] = 1;
50             x[i] = a;y[i] =b;
51         }
52         int ans = hungary();
53         for(int i = 0 ;i < k ; i++)
54         {
55             map[x[i]][y[i]] = 0;
56             res = hungary();
57             if(res == ans)
58                 count ++;
59             map[x[i]][y[i]] = 1;
60         }
61         printf("Board %d have %d important blanks for %d chessmen.\n",t++,k-count,ans);
62         
63     }
64     return 0;
65 }