SPOJ Problem Set (classical)
206. Bitmap
Problem code: BITMAP

There is given a rectangular bitmap of size n*m. Each pixel of the bitmap is either white or black, but at least one is white. The pixel in
ith line and jth column is called the pixel (i,j). The distance between two pixels
p_{1}=(i_{1},j_{1}) and p_{2}=(i_{2},j_{2}) is defined as:
d(p_{1},p_{2})=i_{1}i_{2}+j_{1}j_{2}.
Task
Write a program which:
 reads the description of the bitmap from the standard input,
 for each pixel, computes the distance to the nearest white pixel,
 writes the results to the standard output.
Input
The number of test cases t is in the first line of input, then t test cases follow separated by an empty line.
In the first line of each test case there is a pair of integer numbers
n, m separated by a single space, 1<=n <=182, 1<=m<=182. In each of the following
n lines of the test case exactly one zeroone word of length
m, the description of one line of the bitmap, is written. On the jth position in the line
(i+1), 1 <= i <= n, 1 <= j <= m, is '1' if, and only if the pixel
(i,j) is
white.
Output
In the ith line for each test case, 1<=i<=n, there
should be written
m integers f(i,1),...,f(i,m) separated by single spaces, where f(i,j) is
the distance from the pixel
(i,j) to the nearest white
pixel.
Example
Sample input:
1
3 4
0001
0011
0110
Sample output:
3 2 1 0
2 1 0 0
1 0 0 1
