MathDB
mastermind game in olympiad problem (Chile NMO 1990 P7)

Source:

November 20, 2021
combinatoricsColoring

Problem Statement

It is about deciphering the code C1C2C3C4C_1C_2C_3C_4 in which each letter is one of the colors: white (B)(B), blue (A)(A), red (R)(R), green (V)(V), black (N)(N) and brown (C)(C) with allowed repetitions. Four were made attempts to decipher it. NAVBNAVB and ACRCACRC have two color hits, but in wrong places. RBACRBAC and VRBAVRBA have one color match in the correct place, and two other color matches, in places incorrect. Determine all combinations compatible with the information.