Below is the original code. Since 10 and 9 are relatively prime, N%10 and N%9 will be different for all N in 1~90. On the other hand, the remanders will be same where N in 1~10 and N in 91~100. def checkio(attempts): A = attempts if len(A)==1: return (10 More

There is a shorter solution as below which is more clear I think :: checkio=lambda S:any(a.endswith(b)for a in S for b in S-{a}) More

Finally...it's really difficult that pasting Whitespace code into CheckIO editor...||||orz More

The solution which might be the shortest is not created by me. More

They are not special solutions....Q___Q||| More