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;
}
}