Problem 4. Make a checkerboard matrix

This problem is far less trivial than it seems. Fun!

Cool.

Nice

Good one

All solutions with score 10 or 11 use the regexp cheat.

nice one

nice

I like this one! came to know about the invhilb function just because of this!

simple Tricky

This solution works on matlab but not here.
function a = checkerboard(n)
theta=pi/2:pi/2:n*pi/2;
a = (sin(theta)'*sin(theta))+cos(theta)'*cos(theta);
end

very good

This is a good problem!

Very nice! ;)

nice!

It is good problem!

good

Good!

Good

Good one

good one

I can not ...

nice problem

Nice

Puzzled me a bit but I'm proud of the final result even if i did 47 lines of code for this haha!

Nice

Nice - I can think of a few ways to do this. I dislike for loops in general so i try to minimise use, but ended up with a single reduced for loop and an eye commands. Enjoy!

function a = checkerboard(n)
a = ones(n);
a(2:2:n^2)=0;
end this code give me right answer in soft,but failed here

Good problem. Helps to understand the uses of logical operators.

The even part n=4 is tricky, Hint: google it

%% cherboard
function [board] = Chekerboard(n)

%% set bord matrix with zeros
board = zeros(n,n);

for j = 1:n
if mod(j,2)==0 %if zero row is even
for i =1:2:n
board(j,i) = 1;
end
else mod(j,2)==1 %if 1, row is odd
for t = 2:2:n
board(j,t) = 1;
end
end
end

this works and easy to understand~
function a = checkerboard(n)
if mod(n,2)==1
b = ones(n,n);
for i=2:2:n^2
b(i)=0;
end
a=b;
else
b = ones(n+1);
for i=2:2:(n+1)^2
b(i)=0;
end
a=b(1:n,1:n);
end
end

I just made
a(2:2:n,1:2:n) = 0;
a(1:2:n,2:2:n) = 0;

rather easy actually

What is the "size" of the solved problem? How is it calculated?

Awesome!

Nice problem :)