public int DetermineWaterVolumeWhenSpringRunsDry(string filePath)
{
Geology geology = CreateStrata(filePath);
var springX = 500;
var springY = 0;
// fill with water
GoDown(springX, springY, geology);
// count spaces with water
var waterVolume = 0;
for (int y = geology.MinY; y < geology.Strata.GetLength(1); y++)
{
for (int x = 0; x < geology.Strata.GetLength(0); x++)
{
if (geology.Strata[x, y] == 'W')
{
waterVolume++;
}
}
}
return(waterVolume);
}
private void GoDown(int x, int y, Geology geology)
{
geology.Strata[x, y] = '|';
while (geology.Strata[x, y + 1] != '#' && geology.Strata[x, y + 1] != 'W')
{
y++;
if (y > geology.MaxY)
{
return;
}
geology.Strata[x, y] = '|';
}
;
do
{
bool goDownLeft = false;
bool goDownRight = false;
// find boundaries
int minX;
for (minX = x; minX >= 0; minX--)
{
if (SpaceTaken(minX, y + 1, geology.Strata) == false)
{
goDownLeft = true;
break;
}
geology.Strata[minX, y] = '|';
if (SpaceTaken(minX - 1, y, geology.Strata))
{
break;
}
}
int maxX;
for (maxX = x; maxX < geology.Strata.GetLength(0); maxX++)
{
if (SpaceTaken(maxX, y + 1, geology.Strata) == false)
{
goDownRight = true;
break;
}
geology.Strata[maxX, y] = '|';
if (SpaceTaken(maxX + 1, y, geology.Strata))
{
break;
}
}
// handle water falling
if (goDownLeft)
{
if (geology.Strata[minX, y] != '|')
{
GoDown(minX, y, geology);
}
}
if (goDownRight)
{
if (geology.Strata[maxX, y] != '|')
{
GoDown(maxX, y, geology);
}
}
if (goDownLeft || goDownRight)
{
return;
}
// fill row
for (int a = minX; a < maxX + 1; a++)
{
geology.Strata[a, y] = 'W';
}
y--;
}while (true);
}
