joj 1873 Power Strings

 1873: Power Strings

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Result	TIME Limit	MEMORY Limit	Run Times	AC Times	JUDGE
	10s	8192K	650	258	Standard

Given two strings  a and  b we define  a*b to be their concatenation. For example, if  a = "abc" and  b = "def" then  a*b = "abcdef". If we think of concatenation as multiplication, exponentiation by a non-negative integer is defined in the normal way:  a^0 = "" (the empty string) and  a^(n+1) = a*(a^n).

Each test case is a line of input representing s, a string of printable characters. For each s you should print the largest n such that s = a^n for some string a. The length of s will be at least 1 and will not exceed 1 million characters. A line containing a period follows the last test case.

Sample Input

abcd

aaaa

ababab

.

Output for Sample Input

1

4

3

 

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This problem is used for contest: 73 

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一个基础的周期串问题。

有更好的办法，不过还是很黄很暴力的枚举吧（大爱各种暴力流水流）...

不过这样写真心跑得很慢...

 

 1 #include <stdio.h>

 2 #include <string.h>

 3 

 4 int main()

 5 {

 6     char s[1000005];

 7     int n;

 8     int i, j;

 9     

10     //freopen("in.txt", "r", stdin);

11     

12     while (scanf("%s", s) == 1, s[0] != '.')

13     {

14         n = strlen(s);

15         

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

17         {

18             if (0 == n % i)

19             {

20                 int ok = 1;

21                 for (j=i; j<n; ++j)

22                 {

23                     if (s[j] != s[j%i])

24                     {

25                         ok = 0;

26                         break;

27                     }

28                 }

29                 if (ok)

30                 {

31                     printf("%d\n", n/i);

32                     break;

33                 }

34             }

35         }

36     }

37     

38     

39     return 0;

40 }