Every grid algorithm needs one primitive: given a cell, which cells are adjacent to it?
Write neighbors(grid, r, c) that returns a list of the in-bounds 4-directional neighbor coordinates of cell (r, c), as (row, col) tuples.
Explore directions in this fixed order and skip any that fall outside the grid:
The grid is a list of lists (a rectangular matrix). A corner cell has 2 neighbors; a center cell has 4. Keeping the order fixed makes every later search deterministic.
def neighbors(grid, r, c):
"""Return in-bounds 4-directional neighbor coords: up, down, left, right."""
# TODO: check up, down, left, right in that order; keep only in-bounds cells
pass
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Every grid algorithm needs one primitive: given a cell, which cells are adjacent to it?
Write neighbors(grid, r, c) that returns a list of the in-bounds 4-directional neighbor coordinates of cell (r, c), as (row, col) tuples.
Explore directions in this fixed order and skip any that fall outside the grid:
The grid is a list of lists (a rectangular matrix). A corner cell has 2 neighbors; a center cell has 4. Keeping the order fixed makes every later search deterministic.
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