608 - Counterfeit Dollar
Given the results of a sensitive balance scale, determine which coin in a set of 12 is counterfeit and whether it's lighter or heavier.
Since there is always one solution per test, the easiest method is a simple brute force to see which combinations are possible.
1 ABCD EFGH even ABCI EFJK up ABIJ EFGH even
K is the counterfeit coin and it is light.
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