freeCodeCamp/curriculum/challenges/chinese/10-coding-interview-prep/project-euler/problem-150-searching-a-triangular-array-for-a-sub-triangle-having-minimum-sum.md

id, title, challengeType, forumTopicId, dashedName

id	title	challengeType	forumTopicId	dashedName
5900f4031000cf542c50ff15	Problem 150: Searching a triangular array for a sub-triangle having minimum-sum	1	301781	problem-150-searching-a-triangular-array-for-a-sub-triangle-having-minimum-sum

--description--

In a triangular array of positive and negative integers, we wish to find a sub-triangle such that the sum of the numbers it contains is the smallest possible.

在下面的示例中，可以很容易地验证标记的三角形满足具有 -42 的总和的条件。

我们希望制作一个包含一千行的三角形数组，因此我们使用一种随机数生成器（称为线性同余生成器）生成 500500 个伪随机数 s_k ，范围为 $±2^{19}$，如下所示：

$$\begin{align} t := & \ 0\\ \text{for}\ & k = 1\ \text{up to}\ k = 500500:\\ & t := (615949 × t + 797807)\ \text{modulo}\ 2^{20}\\ & s_k := t − 219\\ \end{align}$$

例如：$s_1 = 273519$、$s_2 = −153582$、s_3 = 450905 等。

然后使用伪随机数组形成我们的三角形数组如下：

$$ s_1 \\ s_2\;s_3 \\ s_4\; s_5\; s_6 \\ s_7\; s_8\; s_9\; s_{10} \\ \ldots $$

Sub-triangles can start at any element of the array and extend down as far as we like (taking-in the two elements directly below it from the next row, the three elements directly below from the row after that, and so on).

The "sum of a sub-triangle" is defined as the sum of all the elements it contains.

Find the smallest possible sub-triangle sum.

--hints--

smallestSubTriangleSum() 应该返回 -271248680。

assert.strictEqual(smallestSubTriangleSum(), -271248680);

--seed--

--seed-contents--

function smallestSubTriangleSum() {

  return true;
}

smallestSubTriangleSum();

--solutions--

// solution required