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.