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

Solution:

public class Solution {
    public int compareVersion(String version1, String version2) {
        String[] strs1 = version1.split("\\.");
        String[] strs2 = version2.split("\\.");
        int i = 0;
        for(; i<strs1.length || i<strs2.length; i++){
            Integer n1 = i<strs1.length ? Integer.valueOf(strs1[i]) : 0;
            Integer n2 = i<strs2.length ? Integer.valueOf(strs2[i]) : 0;
            int compare = n1.compareTo(n2);
            if(compare!=0) return compare;
        }
        return 0;
    }
}