[Leetcode] 14. Longest Common Prefix

題目 : 14. Longest Common Prefix

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.

1.

class Solution:
    def longestCommonPrefix(self, strs: List[str]) -> str:
    		 #建立空的ans字串存重複的字母
        ans = ""
        # 先將字串集做排序
        strs = sorted(strs)
        # 比對第一個字串(shortest)和最後一個字串(longest)
        first = strs[0]
        last = strs[-1]
        #用for迴圈逐一比對
        for i in range(min(len(first),len(last))):
            if (first[i]!=last[i]):
                return ans
            ans = ans + first[i]
        return ans