freeCodeCamp/curriculum/challenges/portuguese/08-coding-interview-prep/project-euler/problem-15-lattice-paths.portuguese.md

---
id: 5900f37b1000cf542c50fe8e
challengeType: 5
title: 'Problem 15: Lattice paths'
videoUrl: ''
localeTitle: 'Problema 15: caminhos da rede'
---

## Description
<section id="description"> Começando no canto superior esquerdo de uma grade de 2 × 2, e somente sendo capaz de se mover para a direita e para baixo, há exatamente 6 rotas para o canto inferior direito. <img class="img-responsive center-block" alt="um diagrama de 6 2 por 2 grades mostrando todas as rotas para o canto inferior direito" src="https://cdn-media-1.freecodecamp.org/imgr/1Atixoj.gif"><p> Quantas dessas rotas estão lá através de um determinado <code>gridSize</code> ? </p></section>

## Instructions
<section id="instructions">
</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>latticePaths(4)</code> deve retornar 70.
    testString: 'assert.strictEqual(latticePaths(4), 70, "<code>latticePaths(4)</code> should return 70.");'
  - text: <code>latticePaths(9)</code> deve retornar 48620.
    testString: 'assert.strictEqual(latticePaths(9), 48620, "<code>latticePaths(9)</code> should return 48620.");'
  - text: <code>latticePaths(20)</code> deve retornar 137846528820.
    testString: 'assert.strictEqual(latticePaths(20), 137846528820, "<code>latticePaths(20)</code> should return 137846528820.");'

```

</section>

## Challenge Seed
<section id='challengeSeed'>

<div id='js-seed'>

```js
function latticePaths(gridSize) {
  // Good luck!
  return true;
}

latticePaths(4);

```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```
</section>