Problem A: Mine Sweeper
The game Minesweeper is played on an n by n grid.
In this grid are hidden m mines, each at a distinct grid location.
The player repeatedly touches grid positions. If a position with a mine
is touched, the mine explodes and the player loses. If a positon not
containing a mine is touched, an integer between 0 and 8 appears denoting
the number of adjacent or diagonally adjacent grid positions that contain
a mine. A sequence of moves in a partially played game is illustrated below.
Here, n is 8, m is 10, blank squares represent the
integer 0, raised squares represent unplayed positions, and the figures
resembling asterisks represent mines. The leftmost image represents
the partially played game. From the first image to the second, the
player has played two moves, each time choosing a safe grid position.
From the second image to the third, the player is not so lucky; he chooses
a position with a mine and therefore loses. The player wins if he
continues to make safe moves until only m unplayed positions
remain; these must necessarily contain the mines.
Your job is to read the information for a partially played game and
to print the corresponding board.
The Input
The first line of input contains a single postitive integer
n <= 10.
The next n lines represent the positions of the mines. Each
line represents the contents of a row using n characters: a period
indicates an unmined positon while an asterisk indicates a mined
position.
The next n lines are each n characters
long: touched positions are denoted by an x, and untouched
positions by a period.
The sample input corresponds to the middle figure above.
The Output
Your output should represent the board, with each position
filled in appropriately. Positions that have been touched
and do not contain a mine should
contain an integer between 0 and 8. If a mine has been
touched, all positions with a mine should contain an asterisk.
All other positions should contain a period.
Sample Input
8
...**..*
......*.
....*...
........
........
.....*..
...**.*.
.....*..
xxx.....
xxxx....
xxxx....
xxxxx...
xxxxx...
xxxxx...
xxx.....
xxxxx...
Output for Sample Input
001.....
0013....
0001....
00011...
00001...
00123...
001.....
00123...