MathDB
Maximum sum for column

Source: Turkey JBMO TST 2024 P2

May 13, 2024
combinatorics

Problem Statement

A real number is written on each square of a 2024×20242024 \times 2024 chessboard. It is given that the sum of all real numbers on the board is 20242024. Then, the board is covered by 1×21 \times 2 or 2×12\times 1 dominos such that there isn't any square that is covered by two different dominoes. For each domino, Aslı deletes 22 numbers covered by it and writes 00 on one of the squares and the sum of the two numbers on the other square. Find the maximum number kk such that after Aslı finishes her moves, there exists a column or row where the sum of all the numbers on it is at least kk regardless of how dominos were replaced and the real numbers were written initially.