60 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			60 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | |||
|  | id: 5900f37b1000cf542c50fe8e | |||
|  | challengeType: 5 | |||
|  | title: 'Problem 15: Lattice paths' | |||
|  | videoUrl: '' | |||
|  | localeTitle: 问题15:格子路径 | |||
|  | --- | |||
|  | 
 | |||
|  | ## Description
 | |||
|  | <section id="description">从2×2网格的左上角开始,只能向右和向下移动,右下角有6条路线。 <img class="img-responsive center-block" alt="6 2乘2网格的图表显示了右下角的所有路线" src="https://i.imgur.com/1Atixoj.gif"><p>通过给定的<code>gridSize</code>有多少这样的路由? </p></section> | |||
|  | 
 | |||
|  | ## Instructions
 | |||
|  | <section id="instructions"> | |||
|  | </section> | |||
|  | 
 | |||
|  | ## Tests
 | |||
|  | <section id='tests'> | |||
|  | 
 | |||
|  | ```yml | |||
|  | tests: | |||
|  |   - text: <code>latticePaths(4)</code>应该返回70。 | |||
|  |     testString: 'assert.strictEqual(latticePaths(4), 70, "<code>latticePaths(4)</code> should return 70.");' | |||
|  |   - text: <code>latticePaths(9)</code>应该返回48620。 | |||
|  |     testString: 'assert.strictEqual(latticePaths(9), 48620, "<code>latticePaths(9)</code> should return 48620.");' | |||
|  |   - text: <code>latticePaths(20)</code>应该返回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> |