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:
0 <= strs.length <= 200
0 <= strs[i].length <= 200
strs[i] consists of only lower-case English letters.
Solution:
- find shortest string
- compare shortest with remaining string of array
- horizontal scan until inequality
- return [:i]
Key:
Horizontal scanning
LCP(S1,…, Sn) = LCP(LCP(LCP(S1,S2),S3), …, Sn)
n iterations -> find previous two LCP to compare next to find next LCP