USACO Hamming Codes

 1 /*{
 2 ID:a4298442
 3 PROB:hamming
 4 LANG:C++
 5 }
 6 */
 7 #include<iostream>
 8 #include<fstream>
 9 #define maxn 500
10 using namespace std;
11 ifstream fin("hamming.in");
12 ofstream fout("hamming.out");
13 //#define fin cin
14 //#define fout cout
15 int hamming(int x,int y,int b)
16 {
17     int ans=0;
18     for(int i=1;i<=b;i++)
19     {
20         int u=x&1,v=y&1;
21         if(u!=v)ans++;
22         x>>=1;y>>=1;
23     }
24     return ans;
25 }
26 int ans[maxn];
27 int main()
28 {
29     int n,b,d;
30     fin>>n>>b>>d;
31     for(int idx=1;idx<=n;idx++)
32     {
33         for(int i=0;i<=1<<(b+1)-1;i++)
34         {
35             int flag=0;
36             for(int j=1;j<idx;j++)
37             {
38                 if(hamming(ans[j],i,b)<d){flag=1;break;}
39             }
40             if(!flag)
41             {
42                 ans[idx]=i;break;
43             }
44         }
45     }
46     for(int i=1;i<n;i++)
47     {
48         fout<<ans[i];
49         if(i%10==0)fout<<endl;else fout<<" ";
50     }
51     fout<<ans[n]<<endl;
52     return 0;
53 }