hdu 3335 最大独立集

有整除关系就建边，然后求最大独立集。

AC代码：

 1 #include <iostream>
 2 #include <cstring>
 3 #include <cstdio>
 4 using namespace std;
 5 
 6 const int N = 1001;
 7 const int M = 1000000;
 8 bool visit[N];
 9 __int64 a[N];
10 int head[N];
11 int mark[N];
12 int n, e;
13 
14 struct Edge
15 {
16     int v, next;
17 } edge[M];
18 
19 void addEdge( int u, int v )
20 {
21     edge[e].v = v;
22     edge[e].next = head[u];
23     head[u] = e++;
24 }
25 
26 int dfs( int u )
27 {
28     for ( int i = head[u]; i != -1; i = edge[i].next )
29     {
30         int v = edge[i].v;
31         if ( !visit[v] )
32         {
33             visit[v] = true;
34             if ( mark[v] == -1 || dfs( mark[v] ) )
35             {
36                 mark[v] = u;
37                 return 1;
38             }
39         }
40     }
41     return 0;
42 }
43 
44 int hunagry()
45 {
46     memset( mark, -1, sizeof(mark) );
47     int res = 0;
48     for ( int i = 1; i <= n; i++ )
49     {
50         memset( visit, 0, sizeof(visit) );
51         res += dfs(i);
52     }
53     return res;
54 }
55 
56 int main()
57 {
58     int t;
59     scanf("%d", &t);
60     while ( t-- )
61     {
62         e = 0;
63         memset( head, -1, sizeof(head) );
64         scanf("%d", &n);
65         for ( int i = 1; i <= n; i++ )
66         {
67             scanf("%I64d", a + i);
68             for ( int j = i - 1; j > 0; j-- )
69             {
70                 if ( a[i] % a[j] == 0 || a[j] % a[i] == 0 )
71                 {
72                     addEdge( j, i );
73                 }
74             }
75         }
76         int ans = n - hunagry();
77         printf("%d\n", ans);
78     }
79     return 0;
80 }

 

posted @ 2015-07-27 18:48  hxy_has_been_used  阅读(202)  评论(0)  编辑  收藏  举报