Longest Common Prefix

 1 public class Solution { 2     //http://blog.csdn.net/fightforyourdream/article/details/14642079 3     public String longestCommonPrefix(String[] strs) { 4         if (strs == null || strs.length == 0) { 5             // bug 2: should not return null. 6             return ""; 7         } 8          9         // Find out the shortest length.10         String s0 = strs[0];11         int len = s0.length();12         for (String s: strs) {13             len = Math.min(len, s.length());14         }15         16         // The index of the character which is examing.17         // Bug 3: 当不会break的时候，结果是错的18         // Bug 4: forget to add int i = 0;19         for (int i = 0; i < len; i++) {20             // Bug 1: forget to write charAt(i);21             char c = s0.charAt(i);22             for (int j = 0; j < strs.length; j++) {23                 if (strs[j].charAt(i) != c) {24                     // Bug 5: write substring to sbustring25                     return s0.substring(0, i);26                 }                27             }28         }29         30         // Never break, means strs[0].0-len is the solution.31         return s0.substring(0, len);32     }33 }