47 lines
		
	
	
		
			866 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
		
		
			
		
	
	
			47 lines
		
	
	
		
			866 B
		
	
	
	
		
			Markdown
		
	
	
	
	
	
|   | --- | ||
|  | id: 5900f4461000cf542c50ff58 | ||
|  | title: 'Problem 217: Balanced Numbers' | ||
|  | challengeType: 5 | ||
|  | forumTopicId: 301859 | ||
|  | dashedName: problem-217-balanced-numbers | ||
|  | --- | ||
|  | 
 | ||
|  | # --description--
 | ||
|  | 
 | ||
|  | A positive integer with k (decimal) digits is called balanced if its first ⌈k/2⌉ digits sum to the same value as its last ⌈k/2⌉ digits, where ⌈x⌉, pronounced ceiling of x, is the smallest integer ≥ x, thus ⌈π⌉ = 4 and ⌈5⌉ = 5. | ||
|  | 
 | ||
|  | So, for example, all palindromes are balanced, as is 13722. | ||
|  | 
 | ||
|  | Let T(n) be the sum of all balanced numbers less than 10n. | ||
|  | 
 | ||
|  | Thus: T(1) = 45, T(2) = 540 and T(5) = 334795890. | ||
|  | 
 | ||
|  | Find T(47) mod 315 | ||
|  | 
 | ||
|  | # --hints--
 | ||
|  | 
 | ||
|  | `euler217()` should return 6273134. | ||
|  | 
 | ||
|  | ```js | ||
|  | assert.strictEqual(euler217(), 6273134); | ||
|  | ``` | ||
|  | 
 | ||
|  | # --seed--
 | ||
|  | 
 | ||
|  | ## --seed-contents--
 | ||
|  | 
 | ||
|  | ```js | ||
|  | function euler217() { | ||
|  | 
 | ||
|  |   return true; | ||
|  | } | ||
|  | 
 | ||
|  | euler217(); | ||
|  | ``` | ||
|  | 
 | ||
|  | # --solutions--
 | ||
|  | 
 | ||
|  | ```js | ||
|  | // solution required | ||
|  | ``` |