LeetCode_OJ【14】Longest Common Prefix

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

找出所有字符串的公共前缀

这道题看着挺简单的，但是做起来却磕磕碰碰，足足提交了四五次才通过，主要是匹配串为""，被匹配串为""等情况没有考虑到。

public class Solution {    public String longestCommonPrefix(String[] strs) {if(strs == null) return null;if(strs.length == 0)return "";String prefix = strs[0];for(int i = 1 ; i < strs.length ; i++){    if(strs[i].length() == 0)return "";for(int j = 0 ; j < strs[i].length() ; j++){if(prefix.length() < j+1)break;if(prefix.charAt(j) != strs[i].charAt(j))prefix = prefix.substring(0,j);if(j == strs[i].length()-1 && prefix.length() > strs[i].length())prefix = prefix.substring(0,j+1);}}        return prefix;    }}