ee1e8abd87
* feat(tools): add seed/solution restore script * chore(curriculum): remove empty sections' markers * chore(curriculum): add seed + solution to Chinese * chore: remove old formatter * fix: update getChallenges parse translated challenges separately, without reference to the source * chore(curriculum): add dashedName to English * chore(curriculum): add dashedName to Chinese * refactor: remove unused challenge property 'name' * fix: relax dashedName requirement * fix: stray tag Remove stray `pre` tag from challenge file. Signed-off-by: nhcarrigan <nhcarrigan@gmail.com> Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>
43 lines
796 B
Markdown
43 lines
796 B
Markdown
---
|
|
id: 5900f4f91000cf542c51000c
|
|
title: 'Problem 397: Triangle on parabola'
|
|
challengeType: 5
|
|
forumTopicId: 302062
|
|
dashedName: problem-397-triangle-on-parabola
|
|
---
|
|
|
|
# --description--
|
|
|
|
On the parabola y = x2/k, three points A(a, a2/k), B(b, b2/k) and C(c, c2/k) are chosen.
|
|
|
|
Let F(K, X) be the number of the integer quadruplets (k, a, b, c) such that at least one angle of the triangle ABC is 45-degree, with 1 ≤ k ≤ K and -X ≤ a < b < c ≤ X.
|
|
|
|
For example, F(1, 10) = 41 and F(10, 100) = 12492. Find F(106, 109).
|
|
|
|
# --hints--
|
|
|
|
`euler397()` should return 141630459461893730.
|
|
|
|
```js
|
|
assert.strictEqual(euler397(), 141630459461893730);
|
|
```
|
|
|
|
# --seed--
|
|
|
|
## --seed-contents--
|
|
|
|
```js
|
|
function euler397() {
|
|
|
|
return true;
|
|
}
|
|
|
|
euler397();
|
|
```
|
|
|
|
# --solutions--
|
|
|
|
```js
|
|
// solution required
|
|
```
|