Step 1:
Assign every of the gamers a singular quantity from the set {0, 1, 2, 3}.
Step 2:
Assign every go well with a singular quantity from the identical set. For instance, D=0, C=1, H=2, S=3.
Step 3:
Wiske sums the cardboard values and takes the end result modulo 4 (name this end result x). Then, Wiske removes the cardboard of participant x.
Step 4:
To decode the end result, Barabas sums the remaining playing cards, and is aware of that yet another card have to be added and that the whole sum modulo 4 have to be x. The go well with of the lacking card can then be uniquely decided.
Instance:
Suske, Sidonia, Lambik, and Jerom are respectively assigned 0, 1, 2, 3, and so they respectively draw coronary heart, coronary heart, membership, spade. Utilizing the instance go well with project in Step 2, the sum is 8, which taken modulo 4 is 0. Due to this fact, Wiske removes Suske’s card.
When Barabas walks in, he sees coronary heart, membership, spade and is aware of Suske’s card is lacking. The sum of the proven playing cards is 6, and the whole sum modulo 4 is 0. As such, the final card’s worth have to be 2, because the earlier/subsequent accessible values would indicate card values of -2 and 6 (not possible). Due to this fact, the final card have to be a coronary heart.
