/**
*
* @author
*/
public class HomeworkAssignment_1 {

public static void main(String[] args) {
   Solution sol = new Solution();
   System.out.println(sol.compareVersions("1", "1") == 0);
   System.out.println(sol.compareVersions("1", "2.0") == -1);
   System.out.println(sol.compareVersions("2.0", "1.0") == 1);
   System.out.println(sol.compareVersions("0.1", "0.2") == -1);
   System.out.println(sol.compareVersions("0.13.1", "0.13.2") == -1);
   System.out.println(sol.compareVersions("1.0", "1.0") == 0);
   System.out.println(sol.compareVersions("6", "6") == 0);
   System.out.println(sol.compareVersions("0", "0") == 0);
   System.out.println(sol.compareVersions("1.1.0", "1.3.1") == -1);
   System.out.println(sol.compareVersions("256", "300.2.1") == -1);
   System.out.println(sol.compareVersions("0.1", "1") == -1);

   System.out.println(sol.compareVersions(".2", ".1.1") == 1);
   System.out.println(sol.compareVersions("3.1.1", "4") == -1);
   System.out.println(sol.compareVersions(".0.4", ".1") == -1);
}

}

class Solution {

public int compareVersions(String ver1, String ver2) {
   // add 0 to head of string if it needed
   if (ver1.charAt(0) == '.') {
         ver1 = "0" + ver1;
   }
   if (ver2.charAt(0) == '.') {
         ver2 = "0" + ver2;
   }

   // split string by .
   // then convert to array of integer
   String [] sp1 = ver1.split("\\.");
   int [] v1 = new int[sp1.length];
   for (int i = 0; i < v1.length; i++) {
         v1[i] = Integer.parseInt(sp1[i]);
   }

Recursive Calculation of the Determinant of a Matrix Write a progr...