BITMAP  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:
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
hide comments
accesss_denied:
20200328 08:35:43
Ac in one go . Easy multisource bfs question. 

sayan_244:
20200322 06:11:10
What's the complexity of the multisource bfs approach? 

manish_thakur:
20200115 13:18:36
for those having confusion in input format, you have to input n strings


manuver:
20191028 14:31:12
for who are getting SIGNALABRT (Runtime error) , your solution might be using more memory then available 

abba5:
20191008 07:22:41
No need to use BFS, DFS simple logic work in O(n^2) 

sonuexpc:
20190928 06:47:41
good question, simple bfs... :) \/ 

rishabh121:
20190830 11:19:02
Chooslo!!!!!!!! 

toolatetostart:
20190602 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:
20190530 11:07:28
@nitishk24 can you share your dp code and logic 

abhibrat:
20190522 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 
Added by:  Piotr Ćowiec 
Date:  20040913 
Time limit:  4s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All 
Resource:  6th Polish Olympiad in Informatics, stage 2 