sdut2383Decode the Strings（循环节）

http://acm.sdut.edu.cn/sdutoj/problem.php?action=showproblem&problemid=2383

一下午卡死在这道题上了 还错了那么多次 郁闷

最后经cz提醒 用求出的循环节对每个字母的循环节取余 算每个位置该输出什么字母

View Code

 1 #include<stdio.h>

 2 #include<string.h>

 3 #define LL long long   

 4 char str[100],ss[10][101];

 5 LL gcd(LL a, LL b)

 6 {

 7     return b==0?a:gcd(b,a%b);

 8 }

 9 int main()

10 {

11     int n,i,j,aa,k,a[100],h[100],x,g,b[100];

12     LL m,s2;

13     while(scanf("%d%lld", &n,&m)!=EOF)

14     {

15         if(n==0&&m==0)

16             break;

17         memset(h,0,sizeof(h));

18         for(i = 1; i <= n ; i++)

19             scanf("%d", &a[i]);

20         getchar();

21         gets(str);

22         g =0;

23         int num = 0;

24         s2 = 1;

25         for(i = 1; i <= n; i++)

26         {

27             if(!h[i])

28             {

29                 num = 0;

30                 x = i;

31                 b[0] = i;

32                 int kk = 0;

33                 while(1)

34                 {

35                     x = a[x];

36                     kk++;

37                     b[kk] = x;

38                     num++;

39                     if(x==i)

40                         break;

41                 }

42                 for(j = 0 ; j < kk ; j++)

43                     h[b[j]] = num;

44                 s2 = s2/gcd(num,s2)*num;

45             }

46         }

47         m = s2-m%s2;

48         if(m==0)

49         {

50             puts(str);

51             continue;

52         }

53         for(i = 1;i <= n; i++)

54         {

55             k = m%h[i];

56             aa = i;

57             for(j = 1; j <= k ; j++)

58             {

59                 aa = a[aa];

60             }

61             printf("%c",str[aa-1]);

62         }

63         puts("");

64     }

65     return 0;

66 }