- the person will think a number between 1-100. The Questionnaire can ask n number of condition, i.e the number is even or odd, the number is perfect square or prime number, sum of squares etc.
Is it possible that a person will finds the number what his friend thinks in my mind. the number should between 1-100 via java code
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1 Answers
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It is certainly possible to find a number between 1 and 100 by asking 100 questions, namely:
Is the number one?
Is the number two?
etc., etc., etc.
It is possible to do it with 7 questions by binary search. Writing the number in base 2, ask:
Is the units bit one?
Is the twos bit one?
Is the fours bit one?
etc., etc., etc.
I don't know anything about Java code, but that's for a different website, anyway.
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2Indeed, even 7 questions of the form "Is the number greater than $x$?" will do. (Hint: start with $x=50$.) The binary expansion technique does, however, have the advantage that you can decide all the questions you will ask in advance. – 2012-03-20