Problem:
Score : 200 points

Problem Statement

You are given an H × W grid.

The squares in the grid are described by H strings, S_1,...,S_H.

The j-th character in the string S_i corresponds to the square at the i-th row from the top and j-th column from the left (1 \leq i \leq H,1 \leq j \leq W).

. stands for an empty square, and # stands for a square containing a bomb.

Dolphin is interested in how many bomb squares are horizontally, vertically or diagonally adjacent to each empty square.

(Below, we will simply say "adjacent" for this meaning. For each square, there are at most eight adjacent squares.)

He decides to replace each . in our H strings with a digit that represents the number of bomb squares adjacent to the corresponding empty square.

Print the strings after the process.

Constraints

1 \leq H,W \leq 50

S_i is a string of length W consisting of # and ..

Input

Input is given from Standard Input in the following format:

H W
S_1
:
S_H

Output

Print the H strings after the process.

The i-th line should contain a string T_i of length W, where the j-th character in T_i corresponds to the square at the i-th row from the top and j-th row from the left in the grid (1 \leq i \leq H, 1 \leq j \leq W).

Sample Input 1

3 5
.....
.#.#.
.....

Sample Output 1

11211
1#2#1
11211

For example, let us observe the empty square at the first row from the top and first column from the left.

There is one bomb square adjacent to this empty square: the square at the second row and second column.

Thus, the . corresponding to this empty square is replaced with 1.

Sample Input 2

3 5
#####
#####
#####

Sample Output 2

#####
#####
#####

It is possible that there is no empty square.

Sample Input 3

6 6
#####.
#.#.##
####.#
.#..#.
#.##..
#.#...

Sample Output 3

#####3
#8#7##
####5#
4#65#2
#5##21
#4#310

Solution in Rust (1.42.0) (judge verdict: Runtime Error)

use std::io;

fn main() {
	// reading H W 
	let mut line = String::new();
	io::stdin().read_line(&mut line).unwrap();
	let vec : Vec<&str> = line.split_whitespace().collect();

	let h : usize = vec[0].parse().unwrap();
	let w : usize = vec[1].parse().unwrap();

	// prepareing h x w grid
	let mut grid = vec![vec!['.'; w]; h];

	// reading strings which stand for empty squares and bomb squares
	for hi in 0..h {
		let mut line = String::new();
		io::stdin().read_line(&mut line).unwrap();
		
		let mut wi = 0;
		for c in line.trim_end().chars() {
			if c == '#' {
				grid[hi][wi] = '#';
			}
			wi += 1;
		}
	}
	
	// preparing arrays for neigher search
	let dw: [i64; 8] = [-1, 0, 1, -1, 1, -1, 0, 1];
	let dh: [i64; 8] = [-1, -1, -1, 0, 0, 1, 1, 1];

	// counting '#' adjacent to each '.' square in grid
	for hi in 0..h {
		for wi in 0..w {
			if grid[wi][hi] == '#' {
				continue;
			}

			let mut cnt = 0;
			for d in 0..8 {
				let nwi = wi as i64 + dw[d];
				let nhi = hi as i64 + dh[d];

				if nwi < 0 || nwi >= w as i64 {
					continue;
				}
				if nhi < 0 || nhi >= h as i64 {
					continue;
				}

				if grid[nwi as usize][nhi as usize] == '#' {
					cnt += 1;
				}
			}
			grid[wi][hi] = cnt.to_string().chars().next().unwrap();
		}
	}

	// output
	for hi in 0..h {
		let mut out_row = String::from("");
		for wi in 0..w {
			out_row.push(grid[wi][hi]);
		}
		println!("{}", out_row);
	}
}