1.1 KiB
1.1 KiB
id | title | challengeType | forumTopicId | dashedName |
---|---|---|---|---|
5900f50a1000cf542c51001c | Problem 413: One-child Numbers | 5 | 302082 | problem-413-one-child-numbers |
--description--
We say that a d
-digit positive number (no leading zeros) is a one-child number if exactly one of its sub-strings is divisible by d
.
For example, 5671 is a 4-digit one-child number. Among all its sub-strings 5, 6, 7, 1, 56, 67, 71, 567, 671 and 5671, only 56 is divisible by 4.
Similarly, 104 is a 3-digit one-child number because only 0 is divisible by 3. 1132451 is a 7-digit one-child number because only 245 is divisible by 7.
Let F(N)
be the number of the one-child numbers less than N
. We can verify that F(10) = 9
, F({10}^3) = 389
and F({10}^7) = 277\\,674
.
Find F({10}^{19})
.
--hints--
oneChildNumbers()
should return 3079418648040719
.
assert.strictEqual(oneChildNumbers(), 3079418648040719);
--seed--
--seed-contents--
function oneChildNumbers() {
return true;
}
oneChildNumbers();
--solutions--
// solution required