Advanced · 2D lists · 183 of 264
Minesweeper numbers
Replace every empty square (.) of a minesweeper field with the number of mines (*) in the 8 squares around it. Mines stay *.
Input: r and c, then r lines of c characters. Output: the field with numbers.
Examples
Input
3 3 *.. ... ..*
Output
*10 121 01*
Input
1 1 .
Output
0
Input
2 4 *.*. .*..
Output
*3*1 2*21
One more test checks other inputs when you press Check.
Stuck? The idea behind 2d lists
A list of lists is a grid: grid[row][col]. Read one row per line, each turned into numbers.
Loop over rows, then over the columns inside each row. zip(*grid) turns rows into columns.
grid = [[1, 2, 3], [4, 5, 6]]
for row in grid:
print(*row)
print(grid[1][2]) # 6Watch for: [[0] * 3] * 2 makes two names for the same row: changing one changes both. Build rows with a comprehension: [[0] * 3 for _ in range(2)].