Longest Common Prefix - LeetCode

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: ["flower","flow","flight"]
Output: "fl"

Example 2:

Input: ["dog","racecar","car"]
Output: ""
Explanation: There is no common prefix among the input strings.

Note:

All given inputs are in lowercase letters a-z.

Java Solution :

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