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 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:
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
satish7978:
2020-07-06 23:14:47
waah. multisource bfs is best. |
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akt_114:
2020-06-19 21:44:06
AC in one go ! Multisource BFS :) |
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egor091:
2020-06-19 16:45:24
AC in one go
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yash_999:
2020-06-16 10:03:06
can be done without multisource bfs using only bfs shortest path with a little optimization ran in 0.5 s
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gaur_gaur:
2020-05-31 08:44:05
simple mutisource bfs question :) |
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joaoabrantes:
2020-05-28 14:52:57
Please take care after output each test, you need to read a empty line after every output, otherwise you gonna get RE |
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prantoru:
2020-05-14 07:30:52
who still could't solve the problem, just goto geeksforgeeks and read the article about multisouce bfs and solve the problem.... :) |
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prantoru:
2020-05-14 06:50:24
what is the maximum value of t....? -_- |
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shuhbo:
2020-05-09 20:03:17
Simple logic. You can solve without bfs and dfs. |
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abhishek_251:
2020-04-25 08:38:58
if you're using multisource bfs keep in mind don't use pair,map etc. theres high chances that you will get TLE. And also no need of visited{true} array.
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Added by: | Piotr Ćowiec |
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 |