Hi, I came across the following problem in StackOverflow. It seems to be a Facebook Programming Challenge. The question was posted more than a year ago and so, I hope I am not violating any rules posting this question here :)

Question Link

I could see one validity test could be to check if difference between every pair of guess cannot be more than the actual difference in various positions of the guesses. But I am not able to validate multiple guesses together. I was trying to model this like some graph problem but could not make any progress. Any hints would be greatly helpful. Thanks in advance :)