14. Longest Common Prefix

public class Solution {
    public String longestCommonPrefix(String[] strs) {
        if (strs==null || strs.length==0){
            return "";
        }
        
        String prefix = strs[0];
        for(int i = 0; i< strs.length;i++){
            int j = 0;
             while(j<strs[i].length() && j<prefix.length()&& strs[i].charAt(j)== strs[0].charAt(j)){
                 j++;
             }
             if(j==0){
                 return "";
             }
             prefix = prefix.substring(0,j);
        }
             
             return prefix;
    }
}