import java.util.*;
public class Solution {
/**
*
* @param strs string字符串一维数组
* @return string字符串
*/
public String longestCommonPrefix (String[] strs) {
if(strs == null || strs.length == 0) return "" ;
String maxPrefix = strs[0] ;
for(int i = 1 ; i < strs.length ; i++) {
maxPrefix = samePrefix(maxPrefix , strs[i]) ;
}
return maxPrefix ;
}
//求取公共前缀
public String samePrefix(String s1 , String s2) {
int i = 0 ;
int j = 0 ;
while (i < s1.length() && j < s2.length()) {
if(s1.charAt(i) != s2.charAt(j)) break ;
i ++ ;
j ++ ;
}
return s1.substring(0 , i) ;
}
}