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:

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
aman5898: 2020-04-10 15:49:53

Ac in one go :p
Simple multisource bfs with dijkstra.

khauf007: 2020-04-10 11:41:28

I am getting TLE repeatedly using multisource bfs i am not able to figure out the problem

accesss_denied: 2020-03-28 08:35:43

Ac in one go . Easy multisource bfs question.

sayan_244: 2020-03-22 06:11:10

What's the complexity of the multisource bfs approach?

manish_thakur: 2020-01-15 13:18:36

for those having confusion in input format, you have to input n strings

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


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