73 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			73 lines
		
	
	
		
			2.9 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
| ---
 | ||
| id: a7bf700cd123b9a54eef01d5
 | ||
| title: No Repeats Please
 | ||
| challengeType: 5
 | ||
| videoUrl: ''
 | ||
| localeTitle: 请不要重复
 | ||
| ---
 | ||
| 
 | ||
| ## Description
 | ||
| <section id="description">返回没有重复连续字母的提供字符串的总排列数。假设提供的字符串中的所有字符都是唯一的。例如, <code>aab</code>应该返回2,因为它总共有6个排列( <code>aab</code> , <code>aab</code> , <code>aba</code> , <code>aba</code> , <code>baa</code> , <code>baa</code> ),但只有2个( <code>aba</code>和<code>aba</code> )没有相同的字母(在这种情况下为<code>a</code> )重复。如果卡住,请记得使用<a href="http://forum.freecodecamp.org/t/how-to-get-help-when-you-are-stuck/19514" target="_blank">Read-Search-Ask</a> 。尝试配对程序。编写自己的代码。 </section>
 | ||
| 
 | ||
| ## Instructions
 | ||
| <section id="instructions">
 | ||
| </section>
 | ||
| 
 | ||
| ## Tests
 | ||
| <section id='tests'>
 | ||
| 
 | ||
| ```yml
 | ||
| tests:
 | ||
|   - text: <code>permAlone("aab")</code>应返回一个数字。
 | ||
|     testString: 'assert.isNumber(permAlone("aab"), "<code>permAlone("aab")</code> should return a number.");'
 | ||
|   - text: <code>permAlone("aab")</code>应返回2。
 | ||
|     testString: 'assert.strictEqual(permAlone("aab"), 2, "<code>permAlone("aab")</code> should return 2.");'
 | ||
|   - text: <code>permAlone("aaa")</code>应该返回0。
 | ||
|     testString: 'assert.strictEqual(permAlone("aaa"), 0, "<code>permAlone("aaa")</code> should return 0.");'
 | ||
|   - text: <code>permAlone("aabb")</code>应该返回8。
 | ||
|     testString: 'assert.strictEqual(permAlone("aabb"), 8, "<code>permAlone("aabb")</code> should return 8.");'
 | ||
|   - text: <code>permAlone("abcdefa")</code>应返回3600。
 | ||
|     testString: 'assert.strictEqual(permAlone("abcdefa"), 3600, "<code>permAlone("abcdefa")</code> should return 3600.");'
 | ||
|   - text: <code>permAlone("abfdefa")</code>应返回2640。
 | ||
|     testString: 'assert.strictEqual(permAlone("abfdefa"), 2640, "<code>permAlone("abfdefa")</code> should return 2640.");'
 | ||
|   - text: <code>permAlone("zzzzzzzz")</code>应该返回0。
 | ||
|     testString: 'assert.strictEqual(permAlone("zzzzzzzz"), 0, "<code>permAlone("zzzzzzzz")</code> should return 0.");'
 | ||
|   - text: <code>permAlone("a")</code>应返回1。
 | ||
|     testString: 'assert.strictEqual(permAlone("a"), 1, "<code>permAlone("a")</code> should return 1.");'
 | ||
|   - text: <code>permAlone("aaab")</code>应该返回0。
 | ||
|     testString: 'assert.strictEqual(permAlone("aaab"), 0, "<code>permAlone("aaab")</code> should return 0.");'
 | ||
|   - text: <code>permAlone("aaabb")</code>应该返回12。
 | ||
|     testString: 'assert.strictEqual(permAlone("aaabb"), 12, "<code>permAlone("aaabb")</code> should return 12.");'
 | ||
| 
 | ||
| ```
 | ||
| 
 | ||
| </section>
 | ||
| 
 | ||
| ## Challenge Seed
 | ||
| <section id='challengeSeed'>
 | ||
| 
 | ||
| <div id='js-seed'>
 | ||
| 
 | ||
| ```js
 | ||
| function permAlone(str) {
 | ||
|   return str;
 | ||
| }
 | ||
| 
 | ||
| permAlone('aab');
 | ||
| 
 | ||
| ```
 | ||
| 
 | ||
| </div>
 | ||
| 
 | ||
| 
 | ||
| 
 | ||
| </section>
 | ||
| 
 | ||
| ## Solution
 | ||
| <section id='solution'>
 | ||
| 
 | ||
| ```js
 | ||
| // solution required
 | ||
| ```
 | ||
| </section>
 |