Euler Problem 40 solution

Time (s): ~0.008

package margusmartseppcode.From_40_to_49;

public class Problem_40 {
 public static void main(String[] args) {
  int size = 100000, result = 1;
  StringBuilder sb = new StringBuilder(size + 200);

  for (int i = 1; sb.length() <= 100000; i++)
   sb.append(i);

  for (int count = 1; count <= size; count *= 10)
   result *= Character.getNumericValue(sb.charAt(count - 1));

  System.out.println(result);
 }
}

Euler Problem 33 solution

Time (s): ~0.001

package margusmartseppcode.From_30_to_39;

public class Problem_33 {
 public static void main(String[] args) {
  int d = 1;
  double ii;

  for (int i = 1; i < 10; i++)
   for (int j = 1; j < i; j++)
    for (double k = 1; k < j; k++) {
     ii = (i * 10 + j) / (k * 10 + i);
     if (ii == j / k)
      d *= ii;
    }

  System.out.println(d);
 }
}