Longest Common Prefix

lc 14

Write a function to find the longest common prefix string amongst an array of strings.

public 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++){
            int j =0;
            while( j < prefix.length() && j < strs[i].length()){
                if( prefix.charAt(j) != strs[i].charAt(j)){
                    break;
                }
                j++;
            }
            if( j == 0){
                return "";
            }
            prefix = prefix.substring(0, j);
        }
        return prefix;
    }
}