Longest Common Prefix leetcode

Write a function to find the longest common prefix string amongst an array of strings.
暴力解法, 先找到所有字符里面最小长度(最长的前缀肯定小于等于这个长度).之后循环, 每个以第零个为参照逐位扫描, 如果不相同则返回当前记录的前缀

public class Solution {
    public String longestCommonPrefix(String[] strs) {
        if (strs.length == 0 || strs == null) {
            return "";
        }
        int min = Integer.MAX_VALUE;
        StringBuilder res = new StringBuilder();
        for (int i = 0; i < strs.length; i++) {
            min = Math.min(min, strs[i].length());
        }
        for (int i = 0; i < min; i++) {
            for (int j = 0; j < strs.length; j++) {
                if (strs[j].charAt(i) != strs[0].charAt(i)) {
                    return res.toString();
                }
            }
            res.append(strs[0].charAt(i));
        }
        return res.toString();
    }
}