---
id: 5900f3e01000cf542c50fef3
title: 'Problem 116: Red, green or blue tiles'
challengeType: 1
forumTopicId: 301742
dashedName: problem-116-red-green-or-blue-tiles
---

# --description--

A row of five black square tiles is to have a number of its tiles replaced with coloured oblong tiles chosen from red (length two), green (length three), or blue (length four).

If red tiles are chosen there are exactly seven ways this can be done.

<img class="img-responsive center-block" alt="將紅色塊放在長度爲 5 個單元的一行中的可能方法" src="https://cdn.freecodecamp.org/curriculum/project-euler/red-green-or-blue-tiles-1.png" style="background-color: white; padding: 10px;" />

If green tiles are chosen there are three ways.

<img class="img-responsive center-block" alt="將綠色塊放在長度爲 5 個單位的一行中的可能方法" src="https://cdn.freecodecamp.org/curriculum/project-euler/red-green-or-blue-tiles-2.png" style="background-color: white; padding: 10px;" />

And if blue tiles are chosen there are two ways.

<img class="img-responsive center-block" alt="將藍色塊放在長度爲 5 個單位的一行中的可能方法" src="https://cdn.freecodecamp.org/curriculum/project-euler/red-green-or-blue-tiles-3.png" style="background-color: white; padding: 10px;" />

假定顏色不能混合，則有 7 + 3 + 2 = 12 種方法來替換長度爲 5 個單位的黑色瓷磚。 如果顏色不能混合且至少必須使用一個彩色瓷塊，那麼一行長度爲50個單位的黑色瓷塊可以有多少種不同的更換方式？

**注意：** 這與問題 117 有關。

# --hints--

`redGreenBlueOne()` 應該返回 `20492570929`。

```js
assert.strictEqual(redGreenBlueOne(), 20492570929);
```

# --seed--

## --seed-contents--

```js
function redGreenBlueOne() {

  return true;
}

redGreenBlueOne();
```

# --solutions--

```js
// solution required
```
