NEG2  The Moronic Cowmpouter
Inexperienced in the digital arts, the cows tried to build a calculating engine (yes, it's a cowmpouter) using binary numbers (base 2) but instead built one based on base negative 2! They were quite pleased since numbers expressed in base 2 do not have a sign bit.
You know number bases have place values that start at 1 (base to the 0 power) and proceed righttoleft to base^1, base^2, and so on. In base 2, the place values are 1, 2, 4, 8, 16, 32, ... (reading from right to left). Thus, counting from 1 goes like this: 1, 110, 111, 100, 101, 11010, 11011, 11000, 11001, and so on.
Eerily, negative numbers are also represented with 1's and 0's but no sign. Consider counting from 1 downward: 11, 10, 1101, 1100, 1111, and so on.
Please help the cows convert ordinary decimal integers (range 2,000,000,000 .. 2,000,000,000) to their counterpart representation in base 2.
Input
A single integer to be converted to base 2
Output
A single integer with no leading zeroes that is the input integer converted to base 2. The value 0 is expressed as 0, with exactly one 0.
Example
Input: 13 Output: 110111
hide comments
rohit1507:
20170913 11:37:26
Spoj brings new concept in every question! _/\_ 

nilabja16180:
20170321 16:04:00
Easy! 

sudeep_11:
20170126 14:36:51
take care of case n=0 it costed me 2 WA's


nonushikhar:
20160313 21:18:02
easy qs :) 

Komal:
20160205 22:17:27
take care of the output statement 

Vmcode:
20151216 19:57:11
nice one, ac in one go! 

vedsar:
20150316 18:47:28
my 100th :) 

agaurav77:
20141211 11:33:17
Remember the cornerstone cases. Learnt something new :) 
Added by:  Nguyen Van Quang Huy 
Date:  20060215 
Time limit:  0.367s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: NODEJS PERL6 VB.NET 
Resource:  USACO FEB06 Bronze Division 