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
imwrkhrd: 2016-08-28 22:46:47

n/m seems to be bigger than 182

hamzaziadeh: 2016-08-13 01:37:05

It gives me re tho its working with me?

cnexans: 2016-08-08 19:09:30

Guessing that it is a metric space

sarthak_8: 2016-08-07 10:10:24

60th on SPOJ. AC in 0.08 sec. Good question. Learnt something new. Must do.

Last edit: 2016-08-07 10:16:38
Dushyant Singh: 2016-07-26 13:35:27

Weird. Declaring 2D char array inside main gives RE and declaring it globally gives AC. o_O

UPD --> More weird thing. If I declare 2D char array before other variables AC else it gives RE! WTF! x_x

Last edit: 2016-07-26 13:48:09
sonali9696: 2016-07-19 17:03:35

My first bfs question ^_^

SANDEEP KUMAR: 2016-07-14 05:34:47

cakewalk, totally flooded it...

iharsh234: 2016-07-09 21:52:18

with simple bfs AC modifies code a bit series of RE comes _/\_

Last edit: 2016-07-09 21:53:48
Deepak : 2016-07-04 13:44:51

finally AC after a in 0.08!!

baadshah_: 2016-06-26 16:09:28

USE BFS AC in 1 GO(0.06s)

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