Compare Version Numbers.java

/*
Compare two version numbers version1 and version1.
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
*/

public class Solution {
	public int compareVersion(String version1, String version2) {
		String[] strs1 = version1.split("\\."), strs2 = version2.split("\\.");
        int i = 0;
        for (; i < Math.min(strs1.length, strs2.length); i++) {
            Integer i1 = Integer.valueOf(strs1[i]), i2 = Integer.valueOf(strs2[i]);
            if (i1 > i2) {
                return 1;
            } else if (i1 < i2) {
                return -1;
            }
        }
        if (strs1.length > strs2.length && Integer.valueOf(strs1[i]) > 0) {
            return 1;
        } else if (strs1.length < strs2.length && Integer.valueOf(strs2[i]) > 0) {
            return -1;
        }
        return 0;
	}
}