Google Code Jam 2017, Qualification Round, readable C solution

C.java

  /**
   * Complexity O(log(k))
   * Terminal recursion
   */
  private static String solve(long n, long k) {
    if (k == 1) {
      long bigHalf = n / 2;
      long smallHalf = (n - 1) - bigHalf;

      return "" + bigHalf + " " + smallHalf;
    }

    boolean k_odd = ((k & 1) == 1);
    boolean n_odd = ((n & 1) == 1);

    if (n_odd) {
      if (k_odd) {
        return solve((n - 1) / 2, (k - 1) / 2);
      }
      else {
        return solve((n - 1) / 2, k / 2);
      }
    }
    else {
      if (k_odd) {
        return solve((n / 2) - 1, (k - 1) / 2);
      }
      else {
        return solve(n / 2, k / 2);
      }
    }
  }