poj 2245 水题

求组合数，dfs即可
 1 #include<cstdio>
 2 #include<iostream>
 3 #include<algorithm>
 4 #include<cstring>
 5 #include<cmath>
 6 #include<queue>
 7 using namespace std;
 8 int N,m,t;
 9 int a[15],vis[15];
10 void dfs(int st,int n)
11 {
12     int i;
13     if(n==6)    //已选择6个
14     {
15         int fl=1;
16         for(i=1;i<=N;i++)
17         {
18             if(vis[i])
19             {
20                 if(fl)  printf("%d",a[i]),fl=0;
21                 else printf(" %d",a[i]);
22             }
23         }
24         printf("
");
25         return;
26     }
27     for(i=st;i<=N;i++)
28     {
29         if(!vis[i])
30         {
31             vis[i]=1;
32             dfs(i+1,n+1);
33             vis[i]=0;
34         }
35     }
36 }
37 int main()
38 {
39     int i,j,k=0;
40     //freopen("1.in","r",stdin);
41     while(scanf("%d",&N)!=EOF&&N>0)
42     {
43         memset(vis,0,sizeof(vis));
44         if(k++) printf("
");
45         for(i=1;i<=N;i++)   cin>>a[i];
46         dfs(1,0);
47     }
48     return 0;
49 }