14. Longest Common Prefix

Problem Link

Description

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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

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Python3

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