Problem 840. SET (the card game)

Created by Matthew Eicholtz

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<a href="http://www.setgame.com/set/index.html">SET</a> is a card game in which players try to find valid 3-card sets from 12 cards on the table. What makes a valid set? Every card has four features, each with three possible values. In a valid set, each of the features, when looked at individually, are either the same on each card OR different on each card.In this problem, you are given a 12x4 matrix representing 12 cards (rows) with 4 features (columns) each. The N-th row corresponds to the N-th card. Each feature has a value of 0, 1, or 2. Create a function that returns an Mx3 matrix of all valid sets, where each row is a set and each column is the index to a card in the set. For every set, the cards (columns) should be arranged in ascending order. If there are no valid sets for a given input, return []. You may assume that all cards are unique.Example<pre class="language-matlab">cards = [1 0 1 0
 1 1 1 1
 2 2 1 0
 0 1 2 2
 2 1 1 1
 1 0 1 2
 0 0 0 0
 2 2 2 2
 0 2 0 0
 1 1 1 0
 0 1 0 2
 0 2 0 2];
</pre>returns<pre class="language-matlab">sets = [2 7 8
 6 8 11]
</pre>because there are two valid sets. Cards 2,7, and 8 make one set and cards 6,8, and 11 form another set. Notice that a card can be a part of more than one set.

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Last Solution submitted on Sep 13, 2020

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Amro on 10 Aug 2012

A related question on Stack Overflow:

Asif Newaz on 15 Feb 2020

i dont understand it properly..how 6,8,11 is a valid set ?

Highphi on 26 Jul 2020

NOTE: That link has moved. It is now HERE: https://www.setgame.com/sites/default/files/instructions/SET%20INSTRUCTIONS%20-%20ENGLISH.pdf

Highphi on 26 Jul 2020

Also, I think you make a 'set' by combining 3 different cards so that, when combined, have 0 1 and 2 in each column or one of those options across entire column

for 2 7 8:
1 1 1 1
0 0 0 0
2 2 2 2
-- has 0, 1, 2 in each column

for 6 8 11,
1 0 1 2
2 2 2 2
0 1 0 2
-- has 0, 1, 2 in first three column and all 2s in last column

Solution Comments

Solution 126182

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Khaled Hamed on 10 Aug 2012

Almost.....!

Solution 115065

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1 Comment

Matthew Eicholtz on 19 Jul 2012

trying to do it without a for-loop

Solution 115047

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Tim on 18 Jul 2012

Using parts of Solution 115046

Solution 115046

1 Comment

1 Comment

Matthew Eicholtz on 18 Jul 2012

Using parts of Solution 114934

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games matrix manipulation

Problem 840. SET (the card game)

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Problem 840. SET (the card game)

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