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14. Longest Common Prefix

Difficulty Topics

Description

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: strs = ["flower","flow","flight"]
Output: "fl"

Example 2:

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

 

Constraints:

  • 1 <= strs.length <= 200
  • 0 <= strs[i].length <= 200
  • strs[i] consists of only lowercase English letters.

Solution

longest-common-prefix.py
class Solution:
    def longestCommonPrefix(self, strs: List[str]) -> str:
        w = min(strs, key = len)
        res = ""

        for i, x in enumerate(w):
            flag = True

            for word in strs:
                if word[i] != x:
                    flag = False
                    break

            if flag:
                res += x
            else:
                break

        return res