All Questions
Tagged with construction no-computers
11
questions
13
votes
4
answers
2k
views
Can you color the 8x8 grid red and blue?
Consider an 8x8 grid made up of 64 unit squares. The goal is to color the 64 squares red or blue so that the following two constraints are satisfied:
ROWS: For every pair of adjacent rows, exactly ...
- 12.5k
6
votes
2
answers
441
views
Pawns and a chessboard with no three aligned
This little problem crossed my mind and appeared to be not quite trivial.
How can you place P pawns on a chessboard with the constraint that no pawn is exactly midway between two other pawns?
Sure ...
- 30.6k
18
votes
7
answers
1k
views
Efficient Mowing at PSE
Your task:
Find the most efficient mowing path around the dark green bushes that mows (passes over) all of the grass (light green).
For those who cannot view the image above, there are 9 rows of 16, ...
- 19.4k
10
votes
2
answers
578
views
Permutations of first 10 natural numbers such that all the prefix sums are distinct
I posted this question on Math SE as well. Did not receive any help.
This is a question that I was asked in a Quant Interview. I would like you all to have a crack at this. I could not find a problem ...
- 201
6
votes
1
answer
608
views
Flat share share
This is a sequel to Gentrification in Chessshire.
Due to the febrile state of the Chesster housing market you and your flat mates are forced to rent out half your place to another group of sharers.
...
- 21.3k
1
vote
1
answer
123
views
Self-indulgent numbers
Let's call a positive integer N self-indulgent of degree K>2 if for every positive integer k<K the following is true:
More than half of the first k multiples N,2N,...,kN of N contain with ...
- 21.3k
32
votes
5
answers
5k
views
How can 3 queens control the white squares?
It is well known that there is no way of arranging 4 queens on a checker board in such a way that every square is occupied or threatened.
Now consider a slight variation where we only need to cover ...
- 10.3k
3
votes
2
answers
588
views
A Puzzle about "Codeforces Subsequences"
I'm quite intrigued by an "easy" problem in recent Codeforces contest: Codeforces Subsequences.
In this problem, you have to create a string $T$ as shortest as possible such that $S = $ &...
- 34.3k
9
votes
1
answer
580
views
Connect the wires without setting off the bomb
You just saw a planted time bomb! Just 5 minutes are remaining until it explodes and as you are in currently in a rural area (no bomb disposal squad) and you know how bombs usually work it is up to ...
user47134
4
votes
2
answers
277
views
Chess Construction Challenge #1-Read First Please!
I'm starting a new series in which I set a very specific goal with a unique (to be more specifically defined here in a bit) answer in which the solver must construct a chess position, sometimes a game,...
- 8,313
10
votes
2
answers
652
views
Missing checkmates in one
Have you ever missed a one-move checkmate and immediately realized it after making your move? If you have, you just might have what it takes to crack this problem. Let's take an example:
g4 e5
...
- 78.6k