[Community Puzzle] Morellet’s random lines

Puzzles
#1

Hi every one

“These lines draw a somewhat strange chess board that you fill with only two colours.” is the only definition of Morellet lines in the Morellet’s random lines puzzle https://www.codingame.com/training/easy/morellets-random-lines.

We are asked to tell if two points have the same color. How should I answer this question with the current definition? There is no clear rule in how the colors are chosen.

I managed to get 100% by assuming that two neighbor areas should not have the same colors. But it is clearly not the case even in the first google image results of “morellet lines”:


https://www.bernardchauveau.com/1353-thickbox_default/francois-morellet-senile-lines-2007.jpg

Maybe I missed something?

Thanks

1 Like
Morellet’s random lines Error on last test "Mind the sign"
#2

We just need to know, are the colours the same.
There are only two.
The points in one, or s+2*n, sector are the same color.

#3

Hi there,

I tried to solve the puzzle Morellet’s random lines. I was thinking I successed because I passed all the tests in the interactive window but when I submit, he failed on the last one “Mind the sign”.
Is people have met the same anoying problem ? Or I messed something in my code ?

Thanks in advance for your help guys.

#4

Maybe two lines are the same?

#5

Hi nicola1, thanks for your answer :slight_smile:
It wasn’t two same lines, it was two same intersection point from two different lines, that I count twice instead of once…

Have a good day

#6

I have problem with Morellet’s random lines. All passed from ide but last one doesn’t pass. I see that someone had that issue, but can’t figure out how he solved it.

#7

Why? Timeout or wrong output?

#8

Sry, from ide all passed, when submitted last one didn’t pass so i don’t know exactly why it didn’t.

#9

Maybe your algorithm is faulty. :wink:

#10

I count all lines between two points (discarding same lines and those where points are on same side) and if that number is odd then NO, if it’s even then YES.

#11

What if three lines meet at the same point?

#12

It should be NO if there are 3 lines between points. If poins are on same side of one of those lines, it is YES.
-4 1 2 4
3
5 4 0
-5 4 0
-5 -1 0
YES

-4 1 4 1
3
5 4 0
-5 4 0
-5 -1 0
NO

#13

Do you have idea what could be wrong?

#14

Hi,
you should consider case where you have one of a or b equal to 0.

#15

In some odd way my code did’nt passed all test via interactive IDE.
BUT managed to get 100% in validation!
After, review some code from other member - I also found possible logical errors there.
Consider review an test cases.

#16

Maybe your code is a bit faulty.

#17

@UPS have you understood why your code failed the tests in IDE? To my understanding, you were lucky that your code passed the validators.

#18

Maybe. But in this case validator tests are inconvenience. This code would not have passed the test.
More over: I carefully readed other solushion (only one published in GO). And found errors. It cant pass obvious test:
0 9 0 -9
1
0 1 1

So I conclude about wrong\incomplete tests on validator\IDE in this pazzle.

#19

the last testcase (mind the sign) really troubled me a long time, till I finally know which part I ignored.
if you also passed all test but the last validator, try to focus on those lines may through the original point, and they also the same lines.

1 Like
#20

Can somebody explains the problem clearly? It is not understood at all from the description. How colors are defined? Some kind of image is helpful for explaining the example.

cc: @nicola