1 public class Solution {
2
3 // 1. Method 1, start from the first one, compare prefix with next string, until end;
4 // 2. Method 2, start from the first char, compare it with all string, and then the second char
5 // I am using method 1 here
6 public String longestCommonPrefix(String[] strs) {
7 if (strs == null || strs.length == 0) {
8 return "";
9 }
10 String prefix = strs[0];
11 for(int i = 1; i < strs.length; i++) {
12 int j = 0;
13 while( j < strs[i].length() && j < prefix.length() && strs[i].charAt(j) == prefix.charAt(j)) {
14 j++;
15 }
16 if( j == 0) {
17 return "";
18 }
19 prefix = prefix.substring(0, j);
20 }
21 return prefix;
22 }
23
24 }