USACO 2.1 Hamming Codes(位运算枚举）

 各种位运算，题意好纠结啊，在翻译帮助下，居然1Y了。。。

 1 /*

 2 ID: cuizhe

 3 LANG: C++

 4 TASK: hamming

 5 */

 6 #include <cstdio>

 7 #include <cstring>

 8 #include <cmath>

 9 #include <algorithm>

10 using namespace std;

11 int que[100];

12 int main()

13 {

14     int n,b,d,i,j,k,top,t,num;

15     freopen("hamming.in","r",stdin);

16     freopen("hamming.out","w",stdout);

17     scanf("%d%d%d",&n,&b,&d);

18     que[1] = 0;

19     top = 1;

20     for(i = 1;i < (1<<b);i ++)

21     {

22         for(j = 1;j <= top;j ++)

23         {

24             t = que[j]^i;

25             num = 0;

26             for(k = 0;k < b;k ++)

27             {

28                 if((1<<k)&t)

29                 num++;

30             }

31             if(num < d)

32             break;

33         }

34         if(j == top+1)

35         {

36             que[++top] = i;

37         }

38         if(top == n) break;

39     }

40     for(i = 1;i <= top;i ++)

41     {

42         if(i%10 == 0)

43         printf("%d\n",que[i]);

44         else if(i == top)

45         printf("%d\n",que[i]);

46         else

47         printf("%d ",que[i]);

48     }

49     return 0;

50 }