0014 - Longest Common Prefix

0014 - 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 "".

Examples

Input: strs = ["flower","flow","flight"] Output: "fl"

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 lower-case English letters.

Java Solution

class Solution {
    public String longestCommonPrefix(String[] strs) {
        if(strs.length == 0) return "";
        String longestPrefix = strs[0];
        
        for(int i = 1; i < strs.length; i++) {
            while(strs[i].indexOf(longestPrefix) != 0) {
                longestPrefix = longestPrefix.substring(0, longestPrefix.length()-1);
            }
        }
        return longestPrefix;
    }
}