1af6e7aa5a
* fix: clean-up Project Euler 321-340 * fix: typo * fix: corrections from review Co-authored-by: Sem Bauke <46919888+Sembauke@users.noreply.github.com> * fix: corrections from review Co-authored-by: Tom <20648924+moT01@users.noreply.github.com> Co-authored-by: Sem Bauke <46919888+Sembauke@users.noreply.github.com> Co-authored-by: Tom <20648924+moT01@users.noreply.github.com>
50 lines
927 B
Markdown
50 lines
927 B
Markdown
---
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id: 5900f4c21000cf542c50ffd4
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title: 'Problem 340: Crazy Function'
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challengeType: 5
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forumTopicId: 301999
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dashedName: problem-340-crazy-function
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---
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# --description--
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For fixed integers $a$, $b$, $c$, define the crazy function $F(n)$ as follows:
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$$\begin{align}
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& F(n) = n - c \\;\text{ for all } n > b \\\\
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& F(n) = F(a + F(a + F(a + F(a + n)))) \\;\text{ for all } n ≤ b.
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\end{align}$$
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Also, define $S(a, b, c) = \displaystyle\sum_{n = 0}^b F(n)$.
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For example, if $a = 50$, $b = 2000$ and $c = 40$, then $F(0) = 3240$ and $F(2000) = 2040$. Also, $S(50, 2000, 40) = 5\\,204\\,240$.
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Find the last 9 digits of $S({21}^7, 7^{21}, {12}^7)$.
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# --hints--
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`crazyFunction()` should return `291504964`.
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```js
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assert.strictEqual(crazyFunction(), 291504964);
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```
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# --seed--
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## --seed-contents--
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```js
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function crazyFunction() {
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return true;
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}
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crazyFunction();
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```
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# --solutions--
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```js
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// solution required
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```
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