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Algorithms & data structures

Classic patterns — search, sort, stacks, queues, and practical complexity-aware code.

3 matches

Game of Life Next State Grid in Python

Compute the next generation of Conway's Game of Life from a 2D grid using the standard three rules with neighbor counting.

game-of-life grid cellular-automaton

Python

def next_state(grid):
    m, n = len(grid), len(grid[0])
    new = [[0] * n for _ in range(m)]
    for r in range(m):
        for c in range(n):
            total = 0
            for dr in (-1, 0, 1):
                for dc in (-1, 0, 1):
                    if dr == 0 and dc == 0:
                        continue
   …

14 0 Open

Algorithms & data structures easy

How to Build a Coordinate Grid with Nested Loops in Python

Generate a 2D list of (row, col) coordinate pairs using nested loops and return the grid structure.

coordinate grid nested loops 2d list

Python

def build_coordinate_grid(rows, cols):
    """Build a 2D grid of (row, col) coordinates using nested loops."""
    grid = []
    for r in range(rows):
        row = []
        for c in range(cols):
            row.append((r, c))
        grid.append(row)
    return grid


if __name__ == "__main__":
    grid = build_coo…

15 0 Open

Algorithms & data structures medium

Set Matrix Zeroes in Python: Markers List Grid Demo

Given a matrix, this code finds all rows and columns that contain a zero and sets every element in those rows and columns to zero, using boolean marker arrays.

matrix arrays algorithm

Python

def set_zeroes(matrix):
    rows, cols = len(matrix), len(matrix[0])
    row_markers = [False] * rows
    col_markers = [False] * cols

    # First pass: record which rows and columns contain zeros
    for i in range(rows):
        for j in range(cols):
            if matrix[i][j] == 0:
                row_markers[i] …

14 0 Open

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