BITMAP - Bitmap

no tags 

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:

d(p1,p2)=|i1-i2|+|j1-j2|.

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 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.

Output

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.

Example

Sample input:
1
3 4
0001
0011
0110

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

hide comments
manuver: 2019-10-28 14:31:12

for who are getting SIGNALABRT (Runtime error) , your solution might be using more memory then available

abba5: 2019-10-08 07:22:41

No need to use BFS, DFS simple logic work in O(n^2)

sonuexpc: 2019-09-28 06:47:41

good question, simple bfs... :) \|/

rishabh121: 2019-08-30 11:19:02

Chooslo!!!!!!!!

toolatetostart: 2019-06-02 11:58:57

do only using multisource bfs,it is nothing but you have to push all source vertices with distance 0 and all same as djikstra

andyy143: 2019-05-30 11:07:28

@nitishk24 can you share your dp code and logic

abhibrat: 2019-05-22 15:04:56

I am getting WA even after using bfs but can't figure out what test case is causing it. Can someone please look at my code https://ideone.com/GHnEOU

scolar_fuad: 2019-04-03 21:10:24

AC in one shot do not use DFS algo if you want to escape TLE just bfs traversal is quite enough for this problem

pavanjupalli: 2019-01-13 17:19:43

when i solve using bfs,it gets tle

unknown_user: 2019-01-08 20:48:37

learned multisource bfs


Added by:Piotr Ɓowiec
Date:2004-09-13
Time limit:4s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All
Resource:6th Polish Olympiad in Informatics, stage 2