HDU2063_过山车_C++

  题目:http://acm.hdu.edu.cn/showproblem.php?pid=2063

 

 

  又是一道二分图匹配的裸题,直接上匈牙利算法

  注意一点它末尾的0结束,是标志着有多组数据……坑……

 

 1 #include<cstdio>
 2 #include<cstdlib>
 3 #include<cstring>
 4 #include<cmath>
 5 #include<iostream>
 6 #include<algorithm>
 7 #include<ctime>
 8 #include<queue>
 9 #define fre(x) freopen(x".in","r",stdin);freopen(x".out","w",stdout)
10 #define Test1 freopen("in.in","r",stdin);freopen("1.out","w",stdout)
11 #define Test2 freopen("in.in","r",stdin);freopen("2.out","w",stdout)
12 using namespace std;
13 typedef long long LL;
14 typedef double db;
15 const double CPS=CLOCKS_PER_SEC,TL=0.98;
16 const int oo=2147483647,N=501,M=1001;
17 int first[N],Next[M],v[M],g[N];
18 bool f[N];
19 inline bool xyl(int x)
20 {
21     int i,k;
22     for (i=first[x];i;i=Next[i])
23     {
24         k=v[i];
25         if (f[k])
26         {
27             f[k]=0;
28             if ((!g[k])||xyl(g[k]))
29             {
30                 g[k]=x;
31                 return 1;
32             }
33         }
34     }
35     return 0;
36 }
37 int main()
38 {
39     int n,na,nb,i,j,ans,x;
40     scanf("%d",&n);
41     while (n)
42     {
43         ans=0;
44         scanf("%d%d",&na,&nb);
45         for (i=1;i<=na;i++) first[i]=0;
46         for (i=1;i<=nb;i++) g[i]=0;
47         for (i=1;i<=n;i++)
48         {
49             scanf("%d%d",&x,&v[i]);
50             Next[i]=first[x];
51             first[x]=i;
52         }
53         for (i=1;i<=na;i++)
54         {
55             for (j=1;j<=nb;j++) f[j]=1;
56             if (xyl(i)) ans++;
57         }
58         printf("%d\n",ans);
59         scanf("%d",&n);
60     }
61     return 0;
62 } 

 

 

 

 

 

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posted @ 2016-11-15 20:04  Hadilo  阅读(467)  评论(0编辑  收藏