1,822 reputation
21133
bio website
location Palo Alto, CA
age 24
visits member for 3 years, 8 months
seen yesterday

Dec
23
revised Two seemingly unrelated puzzles have very similar solutions; what's the connection?
deleted 53 characters in body
Dec
22
revised When the roulette has hit 5 reds why shouldn't I bet to black?
deleted 646 characters in body
Dec
22
answered When the roulette has hit 5 reds why shouldn't I bet to black?
Dec
22
comment Two seemingly unrelated puzzles have very similar solutions; what's the connection?
Your updated solution definitely works!
Dec
21
revised Two seemingly unrelated puzzles have very similar solutions; what's the connection?
added 272 characters in body
Dec
21
comment Two seemingly unrelated puzzles have very similar solutions; what's the connection?
Finally, if there's truly no deep connection, I think that "why do they have this common subproblem and where else does this subproblem come up" would still be an interesting question.
Dec
21
comment Two seemingly unrelated puzzles have very similar solutions; what's the connection?
Some great insights here! I definitely agree with you that both graphs and permutations come up. In fact, I would argue that these insights are vital for solving the puzzles in the first place. However, I disagree with you on a few points. In particular, I don't think that (1) a boolean array of size m is constant memory, or that (2) removing a[1] makes problem 6b look like the locker puzzle (since the cycle in problem 6b could start anywhere in the array, while you're always stuck in a cycle for the locker puzzle).
Dec
21
comment Two seemingly unrelated puzzles have very similar solutions; what's the connection?
In the case where only one entry is duplicated, I imagine you could just sum the array values and subtract $2 + 3 + \ldots + n$ to find the duplicate entry :) OK, so technically that requires storing an integer on the order of n^2 (which might not be allowed), but I'm going to sweep that one under the rug because on any "real" computer that would be the sensible thing to do...
Dec
21
revised Two seemingly unrelated puzzles have very similar solutions; what's the connection?
added 6 characters in body; added 6 characters in body
Dec
21
revised Two seemingly unrelated puzzles have very similar solutions; what's the connection?
added 53 characters in body; edited title; edited title
Dec
21
revised Two seemingly unrelated puzzles have very similar solutions; what's the connection?
added 49 characters in body; added 38 characters in body
Dec
21
asked Two seemingly unrelated puzzles have very similar solutions; what's the connection?
Dec
21
comment Seating friends around a dinner table
Thanks, this is quite nice! MUCH nicer than trying to remove someone while maintaining enough friends for the remaining people (in the case where n is even).
Dec
20
accepted Cutting a unit square into smaller squares
Dec
20
awarded  Reversal
Dec
20
accepted Seating friends around a dinner table
Dec
20
comment Seating friends around a dinner table
If you have time, I would really appreciate that!
Dec
20
comment What is the second principle of finite induction?
I actually never thought about that... I guess we implicitly use strong induction whenever we use induction on say, the order of a group.
Dec
20
asked Seating friends around a dinner table
Dec
20
awarded  Nice Question