1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
|
//
// See ../README.md
//
//
// Run as: ln ch-2.java ch2.java; javac ch2.java; java ch2 < input-file
//
import java.util.*;
public class ch2 {
public static int substrings (String n, int m, int prefix, int max) {
if (n . length () == 0) {
return prefix > -1 &&
prefix < max &&
prefix % m == 0 ? 1 : 0;
}
int fc = Integer . parseInt (n . substring (0, 1));
int n_prefix = 10 * (prefix == -1 ? 0 : prefix) + fc;
String tail = n . substring (1, n. length ());
return substrings (tail, m, n_prefix, max) +
substrings (tail, m, prefix, max);
}
public static void main (String [] args) {
Scanner scanner = new Scanner (System . in);
while (scanner . hasNextInt ()) {
int n = scanner . nextInt ();
int m = scanner . nextInt ();
System . out . println (
substrings (Integer . toString (n), m, -1, n));
}
}
}
|
