827 B
827 B
id | title | challengeType | forumTopicId | dashedName |
---|---|---|---|---|
5900f40d1000cf542c50ff1f | Problem 160: Factorial trailing digits | 5 | 301794 | problem-160-factorial-trailing-digits |
--description--
For any N
, let f(N)
be the last five digits before the trailing zeroes in N!
.
For example,
\begin{align}
& 9! = 362880 \\; \text{so} \\; f(9) = 36288 \\\\
& 10! = 3628800 \\; \text{so} \\; f(10) = 36288 \\\\
& 20! = 2432902008176640000 \\; \text{so} \\; f(20) = 17664
\end{align}$$
Find $f(1,000,000,000,000)$
# --hints--
`factorialTrailingDigits()` should return `16576`.
```js
assert.strictEqual(factorialTrailingDigits(), 16576);
```
# --seed--
## --seed-contents--
```js
function factorialTrailingDigits() {
return true;
}
factorialTrailingDigits();
```
# --solutions--
```js
// solution required
```