[14] Longest Common Prefix

https://leetcode.com/problems/longest-common-prefix/description/

• algorithms
• Easy (32.30%)
• Source Code: 14.longest-common-prefix.py
• Total Accepted: 442.6K
• Total Submissions: 1.3M
• Testcase Example: '["flower","flow","flight"]'

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

If there is no common prefix, return an empty string "".

Example 1:

Input: ["flower","flow","flight"] Output: "fl"

Example 2:

Input: ["dog","racecar","car"] Output: "" Explanation: There is no common prefix among the input strings.

Note:

All given inputs are in lowercase letters a-z.

class Solution(object):
    def longestCommonPrefix(self, strs):
        """
        :type strs: List[str]
        :rtype: str
        """
        if not strs: return ''
        return reduce(self.commonOfTwo, strs)

    def commonOfTwo(self, s1, s2):
        if not s1 or not s2: return ''

        len1, len2 = len(s1), len(s2)
        ret = ''
        for i in range(min(len1, len2)):
            if s1[i] == s2[i]:
                ret += s1[i]
            else:
                break

        return ret
#
#
# s = Solution()
# print s.longestCommonPrefix([])