*From Chris Pine, Learn to Program
Hey All --
In the below source code they array is called in the method as x, y,
but the "if" statements are looking to [y][x]. Can anyone explain to
me why they are switched? If you make them [x][y] it still outputs
the correct number (23).
Thanks in advance,
Jordan
## Start of Example
# These are just to make the map
# easier for me to read. "M" is
# visually more dense than "o".
M = ' land '
o = ' water '
world = [[o,o,o,o,o,o,o,o,o,o,o],
[o,o,o,o,M,M,o,o,o,o,o],
[o,o,o,o,o,o,o,o,M,M,M],
[o,o,o,M,o,o,o,o,o,M,o],
[o,o,o,M,o,M,M,o,o,o,o],
[o,o,o,o,M,M,M,M,o,o,o],
[o,o,o,M,M,M,M,M,M,M,o],
[o,o,o,M,M,o,M,M,M,o,o],
[o,o,o,o,o,o,M,M,o,o,o],
[M,M,o,o,o,M,o,o,o,o,o],
[o,o,o,o,o,o,o,o,o,o,o]]
def continent_size world, x, y
if x > 10 && y > 10
size = 0
else
if world[x][y] != ' land '
return 0
end
end
# Either it ' s water or we already
# counted it, but either way, we don ' t
# want to count it now.
# So first we count this tile...
size = 1
world[x][y] = ' counted land '
# ...then we count all of the
# neighboring eight tiles (and,
# of course, their neighbors by
# way of the recursion).
size = size + continent_size(world, x-1, y-1)
size = size + continent_size(world, x , y-1)
size = size + continent_size(world, x+1, y-1)
size = size + continent_size(world, x-1, y )
size = size + continent_size(world, x+1, y )
size = size + continent_size(world, x-1, y+1)
size = size + continent_size(world, x , y+1)
size = size + continent_size(world, x+1, y+1)
size
end
puts continent_size(world, 5, 5)
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