5-island_perimeter.py

#!/usr/bin/python3
"""Answer to one of the interview Questions
A module for working with grid structures.
"""


def island_perimeter(grid: list) -> int:
    """Computes the perimeter of the island described in the grid.

    Args:
        grid (list of list of integers): For each integer, 0 represents
                                         water and 1 represents land.

    Returns:
        int: the perimeter of the island.
    """
    perimeter = 0
    rows = len(grid)
    for i in range(rows):
        cols = len(grid[i])
        for j in range(cols):
            if (grid[i][j] == 1):
                left = 1 if j == 0 or grid[i][j - 1] == 0 else 0
                top = 1 if i == 0 or grid[i - 1][j] == 0 else 0
                right = 1 if j == cols - 1 or grid[i][j + 1] == 0 else 0
                bottom = 1 if i == rows - 1 or grid[i + 1][j] == 0 else 0
                perimeter += (top + right + bottom + left)
    return perimeter