Leetcode14 最长公共前缀

class Solution {
    public String longestCommonPrefix(String[] strs) {
        //如果数组为空
        if(strs == null || strs.length == 0 )
            return "";
        if(strs.length == 1)
            return strs[0];
        String nowStr = commmon(strs[0],strs[1]);
        for(int i=2;i<strs.length;i++){
            nowStr = commmon(nowStr,strs[i]);
            if(nowStr.length() == 0 )
                return nowStr;
        }
        return nowStr;

    }

    //两个中最长
    public String commmon(String s1,String s2){
        int length = Math.min(s1.length(),s2.length());
        String s = "";
        for(int i = 0;i<length;i++){
            if(s1.charAt(i) != s2.charAt(i))
                return s;
            else
                s +=s1.charAt(i);
        }
        return s;
    }
}