The challenge
Create a function that checks if a number n is divisible by two numbers x AND y. All inputs are positive, non-zero digits.
Examples
1) n = 3, x = 1, y = 3 => true because 3 is divisible by 1 and 3
2) n = 12, x = 2, y = 6 => true because 12 is divisible by 2 and 6
3) n = 100, x = 5, y = 3 => false because 100 is not divisible by 3
4) n = 12, x = 7, y = 5 => false because 12 is neither divisible by 7 nor 5
The solution in Java code
Option 1:
public class DivisibleNb {
public static Boolean isDivisible(long n, long x, long y) {
return (n%x ==0) && (n%y ==0);
}
}
Option 2:
import java.util.Arrays;
public class DivisibleNb {
public static Boolean isDivisible(long n, long x, long y) {
return Arrays.asList(x, y).stream().allMatch(i -> n % i == 0);
}
}
Test cases to validate our solution
import static org.junit.Assert.*;
import java.util.Random;
import org.junit.Test;
public class DivisibleNbTests {
@Test
public void test1() {
assertEquals(true, DivisibleNb.isDivisible(12,4,3));
}
@Test
public void test2() {
assertEquals(false, DivisibleNb.isDivisible(3,3,4));
}
@Test
public void test3() {
assertEquals(false, DivisibleNb.isDivisible(8,3,4));
}
@Test
public void test4() {
assertEquals(true, DivisibleNb.isDivisible(48,3,4));
}
@Test
public void test5() {
assertEquals(true, DivisibleNb.isDivisible(100,5,10));
}
@Test
public void test6() {
assertEquals(false, DivisibleNb.isDivisible(100,5,3));
}
@Test
public void test7() {
assertEquals(true, DivisibleNb.isDivisible(4,4,2));
}
@Test
public void test8() {
assertEquals(false, DivisibleNb.isDivisible(5,2,3));
}
@Test
public void test9() {
assertEquals(true, DivisibleNb.isDivisible(1000000,1000000,1000000));
}
@Test
public void test10() {
assertEquals(false, DivisibleNb.isDivisible(1,1000000,1000000));
}
@Test
public void test11() {
Random rnd = new Random();
for (int i = 0; i < 50; i++) {
long r = rnd.nextLong();
long n = 100000 * r;
long k = 100 * r + rnd.nextInt(2);
long l = 10 * r;
System.out.println("Divisible n : " + n + " ? by : " + k + " and : " + l);
assertEquals((n%k == 0) && (n%l == 0), DivisibleNb.isDivisible(n, k, l));
}
}
}
