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Oleksii and Solomiya go pro gaming on a grid

Source: Ukrainian Mathematical Olympiad 2024. Day 2, Problem 8.8, 9.8

March 20, 2024
combinatoricsgame

Problem Statement

Oleksii and Solomiya play the following game on a square 6n×6n6n\times 6n, where nn is a positive integer. Oleksii in his turn places a piece of type FF, consisting of three cells, on the board. Solomia, in turn, after each move of Oleksii, places the numbers 0,1,20, 1, 2 in the cells of the figure that Oleksii has just placed, using each of the numbers exactly once. If two of Oleksii's pieces intersect at any moment (have a common square), he immediately loses.
Once the square is completely filled with numbers, the game stops. In this case, if the sum of the numbers in each row and each column is divisible by 33, Solomiya wins, and otherwise Oleksii wins. Who can win this game if the figure of type FF is: a) a rectangle ; b) a corner of three cells?
Proposed by Oleksii Masalitin