Monthly Archives: February 2014

Decoding the mysterious symmetry of the bicycle lock numbers

Posted on 2014-02-25 by Robin Houston

Suppose you have a lock of this sort that has n dials and k numbers on each dial. Let m(n, k) be the minimum number of turns that always suffice to open the lock from any starting position, where a turn … Continue reading →

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The bicycle lock problem

Posted on 2014-02-18 by Robin Houston

Don’t lock your bicycle with a combination lock. Someone will steal it: I learnt this the hard way. It’s quite easy to open a combination lock by feel, without knowing the combination. Try it: with a bit of practice, you … Continue reading →

Posted in algorithms, Mathematics | 4 Comments