Created
May 9, 2011 03:30
-
-
Save stphung/962009 to your computer and use it in GitHub Desktop.
Implementation of paint bucket operation using bfs
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
import java.util.Arrays; | |
import java.util.LinkedList; | |
import java.util.Queue; | |
public class PaintBucket { | |
public static void main(String[] args) { | |
int[][] colors = new int[][] {{2,2,0,1}, | |
{1,0,0,0}, | |
{0,0,0,1}, | |
{1,1,1,1}}; | |
int x = 0; | |
int y = 0; | |
int fill = 0; | |
bfs(colors,x,y,fill); | |
for(int i=0; i<colors.length; i++) { | |
System.out.println(Arrays.toString(colors[i])); | |
} | |
} | |
public static void bfs(int[][] colors, int r, int c, int fill) { | |
boolean[][] visited = new boolean[colors.length][colors.length]; | |
for(int i=0; i<visited.length; i++) { | |
Arrays.fill(visited[i],false); | |
} | |
Queue<Location> q = new LinkedList<Location>(); | |
q.add(new Location(r,c)); | |
int replace = colors[r][c]; | |
while (!q.isEmpty()) { | |
Location loc = q.remove(); | |
visited[loc.r][loc.c] = true; | |
colors[loc.r][loc.c] = fill; | |
putIfValid(loc.r+1,loc.c-1,replace,q,visited,colors); | |
putIfValid(loc.r+1,loc.c,replace,q,visited,colors); | |
putIfValid(loc.r+1,loc.c+1,replace,q,visited,colors); | |
putIfValid(loc.r-1,loc.c-1,replace,q,visited,colors); | |
putIfValid(loc.r-1,loc.c,replace,q,visited,colors); | |
putIfValid(loc.r-1,loc.c+1,replace,q,visited,colors); | |
putIfValid(loc.r,loc.c+1,replace,q,visited,colors); | |
putIfValid(loc.r,loc.c-1,replace,q,visited,colors); | |
} | |
} | |
public static void putIfValid(int r, int c, int replace, Queue<Location> q, boolean[][] visited, int[][] colors) { | |
if (valid(r,c,replace,visited,colors)) { | |
q.add(new Location(r,c)); | |
} | |
} | |
public static boolean valid(int r, int c, int replace, boolean[][] visited, int[][] colors) { | |
return r >= 0 && r < visited.length && | |
c >= 0 && c < visited.length && | |
!visited[r][c] && colors[r][c] == replace; | |
} | |
private static class Location { | |
private final int r; | |
private final int c; | |
public Location(int r, int c) { | |
this.r = r; | |
this.c = c; | |
} | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment