The first-round interview was conducted online and focused on a simulation-style coding problem. The interviewer described a two-dimensional game board containing two types of pieces.

The first task was to design a class representing the board and implement a method to add a new piece from the bottom of a column, causing existing pieces in that column to shift upward.

The second task involved checking whether any column contained identical pieces, and the third extended this to rows.

The interviewer was friendly and emphasized clear reasoning and clean code design.

You are given a 2D board with two types of pieces. Implement a class that supports adding a piece to a column (pieces shift upward) and methods to check whether any column or row consists entirely of the same piece type.