Interview Question for SDE1s


Country: United States




Comment hidden because of low score. Click to expand.
0
of 2 vote

Here's a 1-line O(1)-time O(1)-space algorithm in python for solving this equation:

print "It doesn't have a solution!"

- 0xF4 September 19, 2015 | Flag Reply
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0
of 0 vote

return is_prime(x)

- emb September 20, 2015 | Flag Reply
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0
of 0 votes

nope, is_prime(x) is a solution for a different equation:
(x-1)! = -1 (mod x)
or (which is the same):
(x-1)! % x = x-1


As written by the author of the question, the equation doesn't have a solution.

- 0xF4 September 20, 2015 | Flag
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0
of 0 vote

Is the question to prove/disprove the inequality?
+ Factorial exists only for non-negative integers....0, 1, 2, 3, .....
+ If x = 0, then (x-1)! == (-1)! is undefined.
+ So, this equation does not hold. I agree with 0xF4.

- smallchallenges September 21, 2015 | Flag Reply
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0
of 0 vote

This is called Wilson's theorem in number theory, this holds iff x is a prime

- eric September 22, 2015 | Flag Reply
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0
of 0 vote

Wilson's prime number.

- adiya.tb September 23, 2015 | Flag Reply


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