您的工作是将此数字作为输入（尽管它也应该与任何其他数字一起使用）：

18349570345710975183495703457109751834957034571097518349570345710975183495703457109761834957034571097518349570345710975183495703457109751834957034571097518349570345710976183495703457109751834957034571097518349570345710975183495703457109751834957034571097618349570345710975183495703457109751834957034571097518349570345710975183495703457109761834957034571097518349570345710975183495703457109751834957034571097518349570345710976183495703457109751834957034571097518349570345710975183495703457109751834957034571097618349570345710975183495703457109751834957034571097518349570345710975183495703457109761834957034571097518349570345710975183495703457109751834957034571097518349570345710976183495703457109751834957034571097518349570345710975183495703457109751834957034571097618349570345710975183495703457109751834957034571097518349570345710975183495703457109761834957034571097518349570345710975183495703457109751834957034571097518349570345710976183495703457109751834957034571097518349570345710975183495703457109751834957034571097618349570345710975183495703457109751834957

并找到最小周期，在这种情况下为：

1834957034571097518349570345710975183495703457109751834957034571097518349570345710976

祝好运并玩得开心点！

说明：

• 输入的数字至少有一个周期和一个局部周期
• 句号始终从输入数字的开头开始
• 在这种情况下，句号表示重复的数字序列。

CJam，20 16字节

Ll:Q{+_Q,*Q#!}=;

从STDIN读取。在线尝试。

上面的代码将需要O（n ²）内存，其中n是输入的长度。只要您有足够的内存，它将可以使用2 ^个16位数字。

这可以解决五个额外字节的开销：

Ll:Q{+_Q,1$,/)*Q#!}=;

运行示例

$ cjam <(echo 'Ll:Q{+_Q,*Q#!}=;') <<< 18349570345710975183495703457109751834957034571097518349570345710975183495703457109761834957034571097518349570345710975183495703457109751834957034571097518349570345710976183495703457109751834957034571097518349570345710975183495703457109751834957034571097618349570345710975183495703457109751834957034571097518349570345710975183495703457109761834957034571097518349570345710975183495703457109751834957034571097518349570345710976183495703457109751834957034571097518349570345710975183495703457109751834957034571097618349570345710975183495703457109751834957034571097518349570345710975183495703457109761834957034571097518349570345710975183495703457109751834957034571097518349570345710976183495703457109751834957034571097518349570345710975183495703457109751834957034571097618349570345710975183495703457109751834957034571097518349570345710975183495703457109761834957034571097518349570345710975183495703457109751834957034571097518349570345710976183495703457109751834957034571097518349570345710975183495703457109751834957034571097618349570345710975183495703457109751834957; echo
1834957034571097518349570345710975183495703457109751834957034571097518349570345710976
$ cjam <(echo 'Ll:Q{+_Q,*Q#!}=;') <<< 12345123451; echo
12345
$ cjam <(echo 'Ll:Q{+_Q,*Q#!}=;') <<< 1234512345; echo
12345
$ cjam <(echo 'Ll:Q{+_Q,*Q#!}=;') <<< 123451; echo
12345

怎么运行的

对于输入Q，想法是重复第一个字符len（Q）并检查结果中Q的索引是否为0。如果不是，请重复前两个字符len（Q）等等。

L                   " Push L := [].                                                       ";
 l:Q                " Read one line from STDIN and save the result in Q.                  ";
    {        }=     " Find the first element q ∊ Q that yields a truthy value:            ";
     +              "   Execute L += [q].                                                 ";
      _Q,*Q#        "   Push (L * len(Q)).index(Q).                                       ";
            !       "   Compute the logical NOT of the index.                             ";
               ;    " Discard the last q. This leaves L on the stack.                     ";

正则表达式（.NET风格），23 22字节

.+?(?=(.*$)(?<=^\1.*))

这将与所需的时间段匹配为子字符串。

在这里测试。

它是如何工作的？

# The regex will always find a match, so there's no need to anchor it to
# the beginning of the string - the match will start there anyway.
.+?        # Try matching periods from shortest to longest
(?=        # Lookahead to ensure that what we've matched is actually
           # a period. By using a lookahead, we ensure that this is
           # not part of the match.
  (.*$)    # Match and capture the remainder of the input in group 1.
  (?<=     # Use a lookahead to ensure that this remainder is the same
           # as the beginning of the input. .NET lookaheads are best
           # read from right to left (because that's how they are matched)
           # so you might want to read the next three lines from the 
           # bottom up.
    ^      # Make sure we can reach the beginning of the string.
    \1     # Match group 1.
    .*     # Skip some characters, because the capture won't cover the
           # entire string.
  )
)

Python 60

s 是数字字符串

[s[:i]for i in range(len(s))if(s[:i]*len(s))[:len(s)]==s][0]

例如：

>>> s = '18349570345710975183495703457109751834957034571097518349570345710975183495703457109761834957034571097518349570345710975183495703457109751834957034571097518349570345710976183495703457109751834957034571097518349570345710975183495703457109751834957034571097618349570345710975183495703457109751834957034571097518349570345710975183495703457109761834957034571097518349570345710975183495703457109751834957034571097518349570345710976183495703457109751834957034571097518349570345710975183495703457109751834957034571097618349570345710975183495703457109751834957034571097518349570345710975183495703457109761834957034571097518349570345710975183495703457109751834957034571097518349570345710976183495703457109751834957034571097518349570345710975183495703457109751834957034571097618349570345710975183495703457109751834957034571097518349570345710975183495703457109761834957034571097518349570345710975183495703457109751834957034571097518349570345710976183495703457109751834957034571097518349570345710975183495703457109751834957034571097618349570345710975183495703457109751834957'
>>> [s[:i]for i in range(len(s))if(s[:i]*len(s))[:len(s)]==s][0]
'1834957034571097518349570345710975183495703457109751834957034571097518349570345710976'

Pyth，14个字符

hf}z*lzTm<zdUz

说明：

implicit:      z = input()
h              head(
 f                  filter(lambda T:
  }z                                z in
    *lz                                  len(z) * 
       T                                          T,
  m                        map(lambda d:
   <zd                                  z[:d],
   Uz                                   range(len(d)))))

本质上，它会生成输入的所有初始序列，每重复一次len(z)，然后查看z输入是否位于结果字符串中。

这不是有效的答案，但是在提出问题后，Pyth最近添加了一项功能，该功能允许使用12个字符的解决方案：

<zf}z*lz<zT1

这将使用整数过滤器。

Japt，8字节

å+ æ@¶îX

尝试一下

-2个字节，感谢Shaggy！

Transpiled JS解释：

// U is the input string representation of the number
U
 // cumulative reduce using the '+' operator
 // the result is an array of strings length 1, 2, ..., N
 // all substrings start with the first character from input
 .å("+")
 // find the first match
 .æ(function(X, Y, Z) {
  // repeat the substring until it is as long as the input
  // and compare it to the input
  return U === U.î(X)
 })

Java 8，125字节

将输入作为字符串，因为除了字符串（没有BigInteger，请使用BigInteger）之外，没有其他合理的方法来表示Java中的1000位数以上的数字。

s->{String o="";for(int i=0;java.util.Arrays.stream(s.split(o+=s.charAt(i++))).filter(b->!b.isEmpty()).count()>1;);return o;}

在线尝试！