LeetCode Longest Common Prefix

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

找出所有字符串的最长公共前缀。

public class Solution {
    public String longestCommonPrefix(String[] strs) {
        String string="";
        String longest="";
        if (strs.length==0) {
            return string;
        }
        for (int i = 1; i <= strs[0].length(); i++) {
            string=strs[0].substring(0, i);
            for (String s : strs) {
                if (!s.startsWith(string)) {
                    return longest;
                }
            }
            longest=string;
        }
        return longest;
    }
}