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
思路:按照"."分割开,然后从头开始对应比较大小。
转义字符需要加\\. http://swiftlet.net/archives/709
public class Solution { public int compareVersion(String version1, String version2) { if(version1==null||version2==null) { return 0; } String[] change1=version1.split("\\."); String[] change2=version2.split("\\."); for(int i=0,j=0;i<change1.length||j<change2.length;) { int v1=i<change1.length?Integer.parseInt(change1[i]):0; int v2=j<change2.length?Integer.parseInt(change2[j]):0; if(v1>v2) { return 1; } else if(v1<v2) { return -1; } i++; j++; } return 0; } }