BZOJ 1854: [Scoi2010]游戏

http://www.lydsy.com/JudgeOnline/problem.php?id=1854

 

武器和属性显然是两个集合相应的关系也很明显，剩下的就是傻逼的找增广路了。找不到直接退出。因为找不到肯定不连续么。

 1 /**************************************************************
 2     Problem: 1854
 3     User: worfzyq
 4     Language: C++
 5     Result: Accepted
 6     Time:3476 ms
 7     Memory:14896 kb
 8 ****************************************************************/
 9  
10 /*
11 by cao ni ma
12 hehe
13 */
14  
15 #include <cstdio>
16 #include <cstring>
17 #include <algorithm>
18 #include <cmath>
19 #include <vector>
20 #include <list>
21 #include <queue>
22 #include <stack>
23 using namespace std;
24 typedef long long LL;
25  
26 const int MAX = 100000+10;
27 const int inf = 0x3f3f3f3f;
28 vector <int> G[MAX];
29 int match[MAX],use[MAX];
30 int n,m;
31 int vis[MAX];
32 void add_edge(int from,int to) {
33     G[from].push_back(to);
34 }
35 void init() {
36  
37     for(int i=0;i<MAX;i++) G[i].clear();
38 }
39 int dfs(int u) {
40     for(int i=0;i<G[u].size();i++) {
41         int v=G[u][i];
42         if(!use[v]) {
43             use[v]=1;
44             if(match[v]==-1||dfs(match[v])) {
45                 match[v]=u;
46                 return true;
47             }
48         }
49     }
50     return false;
51 }
52  
53 int Full_match () {
54     memset(match,-1,sizeof(match));
55     int res=0;
56     for(int i=1;i<MAX;i++) {
57         memset(use,0,sizeof(use));
58         if(dfs(i)) res++;
59         else break;
60     }
61     return res;
62 }
63  
64 int main()
65 {
66     //freopen("in","r",stdin);
67     //freopen("out","w",stdout);
68     int a,b;
69     while(scanf("%d",&n)==1) {
70         init();
71         for(int i=1;i<=n;i++) {
72             scanf("%d %d",&a,&b);
73             add_edge(a,i);
74             add_edge(b,i);
75         }
76         int ans=Full_match() ;
77         printf("%d\n",ans);
78     }
79     return 0;

80 }