[leetcode] 459. Repeated Substring Pattern @ python

最新推荐文章于 2022-09-30 16:33:48 发布

原创最新推荐文章于 2022-09-30 16:33:48 发布 · 303 阅读

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本文介绍了一种通过检查字符串是否可以由其子串重复拼接而成的方法。利用Python实现了一个解决方案，该方案通过遍历所有可能的子串长度来判断原字符串是否符合题目要求。

原题

Given a non-empty string check if it can be constructed by taking a substring of it and appending multiple copies of the substring together. You may assume the given string consists of lowercase English letters only and its length will not exceed 10000.

Example 1:

Input: “abab”
Output: True
Explanation: It’s the substring “ab” twice.
Example 2:

Input: “aba”
Output: False
Example 3:

Input: “abcabcabcabc”
Output: True
Explanation: It’s the substring “abc” four times. (And the substring “abcabc” twice.)

解法

从可能的子字符串的长度推算, 子字符串最短长度为1, 最长长度为len(s)//2, 遍历可能的长度, 如果能被len(s) 整除, 检查重复子字符串能否构成s.

代码

class Solution(object):
    def repeatedSubstringPattern(self, s):
        """
        :type s: str
        :rtype: bool
        """
        l = len(s)
        for length in range(1, l//2+1):
            if l % length == 0:
                sub = s[:length]
                repeat = l//length
                if sub * repeat == s:
                    return True
        
        return False