public class NumberOfZeros
1: //NumberOfZeros.java
2:
3: import java.util.Scanner;
4:
5: public class NumberOfZeros
6: {
7: public static void main(String[] args)
8: {
9: System.out.print("\nEnter a nonnegative integer: ");
10: Scanner keyboard = new Scanner(System.in);
11: int number = keyboard.nextInt();
12: System.out.println(number + " contains " +
13: getNumberOfZeros(number) + " zeros.");
14: }
15:
16: /**
17: Precondition: n >= 0
18: Returns the number of zero digits in n.
19: */
20: public static int getNumberOfZeros(int n)
21: {
22: int result;
23:
24: if (n == 0)
25: result = 1;
26: else if (n < 10)
27: result = 0; //n has one digit that is not 0
28: else if (n % 10 == 0)
29: result = getNumberOfZeros(n / 10) + 1;
30: else //n % 10 != 0
31: result = getNumberOfZeros(n / 10);
32:
33: return result;
34: }
35: }
36: