leetcode--Compare Version Numbers

Compare two version numbers version1 and version2.
If version1 > version2 return 1, if version1 < version2 return -1, otherwise return 0.

You may assume that the version strings are non-empty and contain only digits and the . character.
The . character does not represent a decimal point and is used to separate number sequences.
For instance, 2.5 is not "two and a half" or "half way to version three", it is the fifth second-level revision of the second first-level revision.

Here is an example of version numbers ordering:

0.1 < 1.1 < 1.2 < 13.37

[java]  view plain  copy

1. public class Solution {  
2.     public int compareVersion(String version1, String version2) {  
3.         String[] v1 = version1.split("\\.");  
4.         String[] v2 = version2.split("\\.");          
5.         int i = 0;  
6.         while(i<v1.length&&i<v2.length){  
7.             int p = Integer.parseInt(v1[i]);              
8.             int q = Integer.parseInt(v2[i]);  
9.             if(p>q){  
10.                 return 1;  
11.             }else if(p<q){  
12.                 return -1;  
13.             }  
14.             i++;  
15.         }  
16.         if(i==v1.length){  
17.             if(i==v2.length){  
18.                 return 0;  
19.             }else{  
20.                 while(i<v2.length){  
21.                     if(Integer.parseInt(v2[i])>0){                         
22.                         return -1;                        
23.                     }  
24.                     i++;  
25.                 }  
26.                 return 0;  
27.             }             
28.         }else{  
29.             while(i<v1.length){  
30.                 if(Integer.parseInt(v1[i])>0){  
31.                     return 1;                     
32.                 }  
33.                 i++;  
34.             }  
35.             return 0;             
36.         }  
37.     }  
38. } 

原文链接http://blog.youkuaiyun.com/crazy__chen/article/details/46388059