// Problem description: https://leetcode.com/problems/longest-common-prefix/description/

​

public class Solution {

    public string LongestCommonPrefix(string[] strs) {

        if(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.Length == 0 )

                    return "";

            }

        }

            return prefix;

    }

}