Exercise 6: Maze Path Finder

Your Task

Write a function has_path(maze, row, col, visited) that:

Returns True if there is a path from (row, col) to the bottom-right corner
Returns False otherwise
0 = wall, 1 = open path
You can move up, down, left, right — not diagonal

Start by calling has_path(maze, 0, 0, set()).

Examples

maze1 = [
    [1, 0, 1],
    [1, 1, 1],
    [0, 0, 1]
]
print(has_path(maze1, 0, 0, set()))  # True
# Path: (0,0) → (1,0) → (1,1) → (1,2) → (2,2)

maze2 = [
    [1, 0, 1],
    [0, 0, 1],
    [0, 0, 1]
]
print(has_path(maze2, 0, 0, set()))  # False
# (0,0) is surrounded — no way through

Hints

💡 Hint 1

Base cases:

Out of bounds → False
Wall (maze[row][col] == 0) → False
Already visited → False
Reached bottom-right → True

💡 Hint 2

For the recursive case, try all 4 directions. Return True if any direction leads to a path — use or:

return (has_path(...up...) or has_path(...down...) or ...)

✅ Solution

def has_path(maze, row, col, visited):
    rows, cols = len(maze), len(maze[0])

    # Base cases
    if row < 0 or row >= rows or col < 0 or col >= cols:
        return False
    if maze[row][col] == 0:
        return False
    if (row, col) in visited:
        return False
    if row == rows - 1 and col == cols - 1:
        return True

    visited.add((row, col))

    return (has_path(maze, row - 1, col, visited) or
            has_path(maze, row + 1, col, visited) or
            has_path(maze, row, col - 1, visited) or
            has_path(maze, row, col + 1, visited))

Maze Path Finder

Exercise 6: Maze Path Finder

Your Task

Examples

Hints

Try it yourself

Code: Maze Path Finder