2024 ways to place domino Indonesia Regional
Source: 2024 Indonesia Regional MO Essay Problem 2
May 6, 2024
dominocombinatoricsChessboardboardBoardsIndonesiaRMO
Problem Statement
Given an board which is divided into squares of size , all of which are white. Then, Aqua selects several squares from this board and colors them black. Ruby then places exactly one domino on the board, so that the domino covers exactly two squares on the board. Ruby can rotate the domino into a domino. After Aqua colors, it turns out there are exactly ways for Ruby to place a domino on the board so that it covers exactly black square and white square.Determine the smallest possible value of so that Aqua and Ruby can do this.Proposed by Muhammad Afifurrahman, Indonesia