BITMAP - Bitmap

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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 i-th line and j-th column is called the pixel (i,j). The distance between two pixels p1=(i1,j1) and p2=(i2,j2) is defined as:



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.


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 zero-one word of length m, the description of one line of the bitmap, is written. On the j-th position in the line (i+1), 1 <= i <= n, 1 <= j <= m, is '1' if, and only if the pixel (i,j) is white.


In the i-th 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.


Sample input:
3 4

Sample output:
3 2 1 0
2 1 0 0
1 0 0 1

hide comments
Rakesh: 2015-06-14 22:12:43

My first with dp using iteration...

reggaeguitar: 2015-04-29 16:59:33

"here 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." See the last part of the sentence, "at least one is white"

Priyanjit Dey: 2015-04-19 20:45:57

ok.. tell what is the output of
r=1 c=1

Abhay: 2015-04-04 20:15:23

Can anyone help me with some test cases? I've tried many test cases but I am getting WA.

soshika: 2015-04-01 00:41:06

multisource bfs :))

Rachit: 2015-03-15 12:44:42

" but at least one is white "

David: 2015-03-03 00:53:34

What if there are no white pixels in the bitmap, what should I print?

scyther: 2015-01-27 13:10:35

you just need one word to understand the ques: minesweeper

Last edit: 2015-01-27 13:12:46
the_imp: 2015-01-24 17:48:08

getting sigxfsz runtime error .....somebody plz help
--edit(Francky)--> Please see the notes below.
1. Don't post any source code here.
sorry about that but can u help me as to why i might be getting that error...

Last edit: 2015-01-24 20:02:01
Arafat dad Khan: 2015-01-22 17:54:01

A brilliant problem with a brilliant solution--- Absolutely loved it

Added by:Piotr Ɓowiec
Time limit:4s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Resource:6th Polish Olympiad in Informatics, stage 2