#grid

16 grid interview questions, asked at Google, OpenAI, Amazon and 12 more companies. Last asked Sep 2026.

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Word search with a word search II follow-upCodingFind words on a letter grid by adjacent moves, then extend the solution to finding many words at once efficiently. Reported on 1point3acres' Glean bank; reconstructed in our own…
Last asked Sep 2026
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Threshold infection spread on a gridCodingA lab tracks a disease across a rectangular field of cells. You are given an m x n grid where 0 is a healthy cell and 1 is an infected cell, and an integer threshold. Each day…
Last asked Sep 2026
Fastest single-mode commute on a city gridCodingYou are planning a commute across a city drawn as a 2D grid of characters: - 'S': your starting point (exactly one). - 'D': your destination (exactly one). - '1' to 'k': a block…
Last asked Sep 2026
Grid maze solver with keys, doors and bombs, AI-assistedCodingYou get a small existing codebase that models a grid maze and an AI assistant you may use. Fix a bug in the provided code, then find the shortest path from start to exit, then add…
Last asked Sep 2026
Rectangle board with remove-at-cell, batch remove and undoCodingBuild a RectangleBoard that holds axis-aligned rectangles on a grid of width columns and height rows. Cells use zero-indexed (x, y), where x is the column and y is the row. A…
Last asked Aug 2026
Max-score grid descent with limited two-row jumpsCodingYou are given an N x M grid of integers board. Rows and columns are numbered from 0, and a cell's value is the score you collect when you visit it. Values may be negative. A path…
Last asked Jul 2026
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Island areas and water boundariesCodingYou are given an m x n grid of characters. Each cell is '1' (land) or '0' (water). Land cells that share a side (up, down, left or right) belong to the same island. Diagonal cells…
Last asked Apr 2026
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Score a tile board by connected terrain regionsCodingA tile-laying board game ends when every player has filled a rectangular board. You must compute a player's final score. You are given board, a 2D list of strings with R rows and…
Last asked Mar 2026
Dot grid game winnerCodingTwo players play a dots-and-boxes style game on a 9 x 9 grid of dots. The grid has 8 x 8 = 64 unit squares ("boxes"). Rows and columns are numbered 0 to 8. You are given moves, a…
Count warehouse robots boxed in on all four sidesCodingA warehouse floor is modeled as an integer grid. Each delivery robot sits at a point (xi, yi), and no two robots share a point. A robot is idle when there is at least one other…
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Largest island perimeter in a gridCodingYou are given an m x n grid where each cell is either land ("1") or water ("0"). Land cells that touch horizontally or vertically (not diagonally) belong to the same island. Treat…
Tallest building between parking lotsCodingA city block is drawn as a rectangular grid of strings. Each tile is one of: - 'P': a parking lot. Its height is fixed at 0. - '-': a lot where a building can go. You choose its…
Type a word on a grid keyboard with a jump limitCodingYou are typing a word with one finger on an unusual keyboard: an m x n grid of characters. Moving the finger from cell (r1, c1) to cell (r2, c2) covers a Manhattan distance of r1…
Two-colour a board with walls and fixed cellsCodingYou are given an M x N board as a matrix of integers. Each cell is one of: - 1: already painted black - 0: already painted white - 9: empty, still to be painted - -1: a wall…
Spell a word on a 5-column letter boardCodingA text-entry device shows the 26 lowercase letters on a board 5 columns wide, filled row by row. Letter c sits at row (ord(c) - ord('a')) // 5 and column (ord(c) - ord('a')) % 5:…
Two cars to their destinations without collisionsCodingA parking robot controls two self-driving cars on a rectangular map. The map is a list of equal-length strings. Each character is one cell: - . is road. - is a wall. Cars cannot…