11 lines
		
	
	
		
			180 B
		
	
	
	
		
			Ruby
		
	
	
	
	
	
			
		
		
	
	
			11 lines
		
	
	
		
			180 B
		
	
	
	
		
			Ruby
		
	
	
	
	
	
| GRID_SIZE = 20
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| 
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| def factorial(num) 
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| 	if(num == 0) 
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| 		return 1
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| 	else 
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| 		return num * factorial(num - 1)
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| 	end
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| end
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| 
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| puts factorial(2 * GRID_SIZE) / factorial(GRID_SIZE) ** 2 | 
