RU-ALLRUSSIAN 1971 Problem 8
An integer is written at each vertex of a regular n- gon. A move is to find four adjacent vertices with numbers a, b, c, d (in that order), so that , and then to interchange b and c. Show that only finitely many moves are possible. For example, a possible sequence of moves is shown below:
Dataset text NuminaMath olympiads. Quoted with source.
Solutions
No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.