14. Longest Common Prefix

標籤：

題目：

Write a function to find the longest common prefix string amongst an array of strings.

連結：http://leetcode.com/problems/longest-common-prefix/

一刷：

class Solution(object):    def longestCommonPrefix(self, strs):        """        :type strs: List[str]        :rtype: str        """        if not strs:            return ‘‘        length = len(strs[0])        common_prefix = [‘‘]        chars_at_idx = set()        for idx in range(length):            for one_string in strs:                if len(one_string) <= idx:                    return ‘‘.join(common_prefix)                chars_at_idx.add(one_string[idx])            if len(chars_at_idx) != 1:                return ‘‘.join(common_prefix)            common_prefix.append(chars_at_idx.pop())        return ‘‘.join(common_prefix)

可以減少中間變數和資料結構的使用：

class Solution(object):    def longestCommonPrefix(self, strs):        """        :type strs: List[str]        :rtype: str        """        if not strs:            return ‘‘        length = len(strs[0])        for idx in range(length):            char = strs[0][idx]            for one_string in strs:                if len(one_string) <= idx or one_string[idx] != char:                    return one_string[:idx]        return strs[0]

 

14. Longest Common Prefix