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>
1.2 KiB
1.2 KiB
id, title, challengeType, videoUrl, dashedName
| id | title | challengeType | videoUrl | dashedName |
|---|---|---|---|---|
| 5900f3881000cf542c50fe9b | 问题28：对角螺旋数 | 5 | problem-28-number-spiral-diagonals |
--description--
从数字1开始，沿顺时针方向向右移动，形成5 x 5螺旋，如下所示：
21 22 23 24 25
20 7 8 9 10
19 6 1 2 11
18 5 4 3 12
17 16 15 14 13
可以验证对角线上的数字之和为101。
以相同方式形成的n×n螺旋中的对角线上的数字的总和是多少？
--hints--
spiralDiagonals(101)应该返回692101。
assert(spiralDiagonals(101) == 692101);
spiralDiagonals(101)应该返回18591725。
assert(spiralDiagonals(303) == 18591725);
spiralDiagonals(101)应该返回85986601。
assert(spiralDiagonals(505) == 85986601);
spiralDiagonals(101)应该返回669171001。
assert(spiralDiagonals(1001) == 669171001);
--seed--
--seed-contents--
function spiralDiagonals(n) {
return n;
}
spiralDiagonals(1001);
--solutions--
const spiralDiagonals = (n) => {
const Sn2 = (n) => {
return n*(n+1)*(2*n+1)/6;
};
const Sn = (n) => {
return n*(n+1)/2;
};
let sum = (Sn2(n-1) + Sn(n-1) + n-1) + (Math.floor(n/2) + Sn2(n));
return sum;
};