Katkat
Back

Implement Connect Four Winner Detection

Virtu FinancialData Scientist · Technical Screen
MediumData ScientistTechnical ScreenCoding & Algorithms

Last updated

This question evaluates the ability to design and implement game-state logic for a Connect Four-style board, covering board data structures, coordinate and boundary handling, gravity-based token placement, and efficient pattern detection for consecutive tokens in the Coding & Algorithms domain.

Implement a Connect Four-style game engine.

The board has 6 rows and 7 columns. Two players alternate turns. On each turn, the current player chooses a column. Because of gravity, the player's token falls to the lowest empty cell in that column. A move is invalid if the chosen column is already full.

After each valid move, determine whether the current player has won. A player wins if they have four of their own tokens consecutively in any of the following directions:

  • Horizontal
  • Vertical
  • Diagonal from bottom-left to top-right
  • Diagonal from top-left to bottom-right

Design and implement the core logic for placing a token and checking whether the latest move creates a win.

Follow-up questions:

  1. How would you support more than two players?
  2. How would you optimize the solution if the board were very large?