Skip to main content

All Questions

Filter by
Sorted by
Tagged with
12 votes
2 answers
621 views

“The Two Sheriffs” puzzle -2: threshold for security

I've already asked a question “The Two Sheriffs” puzzle with wrong assumption. Yoav Kallus in his amazing answer using Fano plane showed that the problem has a solution in the case of seven suspects. ...
Alexey Ustinov's user avatar
6 votes
1 answer
441 views

Minimum number of operations necessary to arrive at any configuration

Let $k \geq 2$ and $N_1, N_2, ..., N_k$ be positive integers. Let $S=\{(a_1,a_2,...,a_k) \in \mathbb{Z}^k:1 \leq a_i \leq N_i\}$ and $A=\{1,2,...,\prod_{i=1}^{k} N_{i}\}$. Given a bijective map $f:...
jack's user avatar
  • 3,153
5 votes
2 answers
496 views

Maximum number of vectors with upper bound on pairwise inner products

I have a collection $\{v_1,...,v_k\}$ of vectors in $\{\pm 1\}^n$ with the property that for all $i\neq j$ we have $\langle v_i, v_j \rangle \le c\log_2(n)$. I am looking for an upper bound on $k$ in ...
DPL's user avatar
  • 63
2 votes
1 answer
262 views

Are there any homomorphic analog error correction code?

Are there any analog error correction codes that are additively and multiplicatively homomorphic?
myshkin's user avatar
  • 41
2 votes
1 answer
316 views

Is this model of converting integers to Gray code correct?

The model shown in the figure converts all numbers that have k digits in the binary system to Gray code without any calculation, but I have no proof that guarantees this claim. Here is some ...
Γιώργος Πλούσος's user avatar