poj 3087 模拟（ELFHash模版，字符串哈希）

 1 #include <iostream>

 2 #include <cstdio>

 3 #include <cstring>

 4 #include <algorithm>

 5 

 6 using namespace std;

 7 

 8 #define MAXN 102

 9 

10 int N,C;

11 char s1[MAXN],s2[MAXN],s12[MAXN<<1],ans[MAXN<<1];

12 

13 //*****************ELFhash***********

14 #define HASH 9901

15 char table[9901][MAXN];

16 int len;

17 int ELFHash(char a[MAXN])        

18 {

19     int h = 0;

20     int x  = 0;

21     for(int i=0;i<len;++i)

22     {

23         h = (h << 4) + (a[i]);

24         if ((x = h & 0xF0000000L) != 0)

25         {

26             h ^= (x >> 24);

27             h &= ~x;

28         }

29     }

30     return h % HASH;

31 }

32 bool is_in(char a[])    //ELFHash函数对字符串判重,没有的时候插入

33 {

34     int i=ELFHash(a);

35     while(strlen(table[i])>0&&strcmp(a,table[i])!=0)

36         i=(i+1)%HASH;

37     if(strlen(table[i])==0)

38     {

39         strcpy(table[i],a);

40         return false;

41     }

42     return true;

43 }

44 //***********************************

45 

46 int main()

47 {

48     scanf("%d",&N);

49     for(int cas=1;cas<=N;cas++)

50     {

51         scanf("%d",&C);getchar();

52         len=C*2;

53         memset(s1,0,sizeof(s1));

54         memset(s2,0,sizeof(s2));

55         memset(s12,0,sizeof(s12));

56         memset(ans,0,sizeof(ans));

57         memset(table,0,sizeof(table));

58         gets(s1);

59         gets(s2);

60         gets(ans);

61         printf("%d ",cas);

62         int step=0;

63         while(1)

64         {

65             step++;

66             for(int i=0;i<len;i+=2)

67                 s12[i]=s2[i/2];

68             for(int i=1;i<len;i+=2)

69                 s12[i]=s1[i/2];

70             s12[len]='\0';

71             //cout<<s1<<endl;

72             //cout<<s2<<endl;

73             if(strcmp(ans,s12)==0)

74             {

75                 printf("%d\n",step);

76                 break;

77             }

78             else if(is_in(s12))

79             {

80                 printf("-1\n");

81                 break;

82             }

83             for(int i=0;i<C;i++)

84                 s1[i]=s12[i];

85             for(int i=0;i<C;i++)

86                 s2[i]=s12[i+C];

87         }

88     }

89     return 0;

90 }