[Solved] 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 “”.

Question

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.

Python Solution

class Solution:
    def longestCommonPrefix(self, strs: List[str]) -> str:
        if len(strs)==0:
            return ''
        shortest = min(strs,key=len)
        for i in range(len(shortest)):
            for word in strs:
                if word[i] != shortest[i]:
                    return shortest[:i]
        return shortest