Count Legal Tic-Tac-Toe Games from the Empty Board
Company: Decagon
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: hard
Interview Round: Technical Screen
Overview: Count every legal Tic-Tac-Toe game sequence from an empty board, treating different move orders as distinct and stopping immediately at the first win or a full board. Practice exhaustive state exploration, correct turn alternation, terminal-state detection, backtracking, and deriving the result rather than hard-coding it.
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