static void tryAddNode(CaveNode next)
{
if (closedNodes.Contains(next))
{
return;
}
CaveNode candidate;
if (openNodes.Contains(next)) //update f and g as necessary
{
openNodes.TryGetValue(next, out candidate);
candidate.costToNode = Math.Min(candidate.costToNode, next.costToNode);
candidate.f = Math.Min(candidate.f, next.f);
}
else
{
openNodes.Add(next);
}
}
public static void Run()
{
Console.WriteLine("\nDay 22");
int[][] erosionGrid;
int[][] terrainGrid;
int targetX;
int targetY;
int depth;
using (StreamReader reader = new StreamReader("input/input22.txt"))
{
depth = int.Parse(reader.ReadLine().Split(' ')[1]);
string[] target = reader.ReadLine().Split(' ', ',');
targetX = int.Parse(target[1]);
targetY = int.Parse(target[2]);
erosionGrid = new int[(targetY + 100)][];
terrainGrid = new int[(targetY + 100)][];
for (int row = 0; row < erosionGrid.Length; row++)
{
erosionGrid[row] = new int[targetX + 100];
terrainGrid[row] = new int[targetX + 100];
}
}
for (int y = 0; y < erosionGrid.Length; y++)
{
for (int x = 0; x < erosionGrid[y].Length; x++)
{
if (targetX == x && targetY == y)
{
erosionGrid[y][x] = depth % 20183;
}
else if (x == 0)
{
if (y == 0)
{
erosionGrid[y][x] = depth % 20183;
}
else
{
erosionGrid[y][x] = (y * 48271 + depth) % 20183;
}
}
else if (y == 0)
{
erosionGrid[y][x] = (x * 16807 + depth) % 20183;
}
else
{
erosionGrid[y][x] = (erosionGrid[y - 1][x] * erosionGrid[y][x - 1] + depth) % 20183;
}
terrainGrid[y][x] = erosionGrid[y][x] % 3;
}
}
Console.WriteLine("Total Risk Level: " + (terrainGrid.Take(targetY + 1).Sum(x => x.Take(targetX + 1).Sum())));
openNodes.Add(new CaveNode(null, 0, 0, targetX, targetY, 0, 0)); //start with torch
while (true)
{
CaveNode currNode = openNodes.FirstOrDefault();
if (currNode.x == targetX && currNode.y == targetY)
{
if (currNode.equipment == 0)
{
Console.WriteLine("Quickest Time to Target: " + currNode.costToNode);
break;
}
else //switch to torch and check other candidates for faster pathing that arrive with the torch already equipped
{
currNode.equipment = 0;
currNode.f += 7;
}
}
else
{
closedNodes.Add(currNode);
openNodes.Remove(currNode);
int terrain;
if (currNode.x > 0) //check if array index is in bounds, then continue with current equipment if possible, else switch to proper equipment
{
terrain = terrainGrid[currNode.y][currNode.x - 1];
if (currNode.equipment != (terrain + 2) % 3)
{
tryAddNode(new CaveNode(currNode, currNode.x - 1, currNode.y, targetX, targetY, terrain, currNode.equipment));
}
else
{
tryAddNode(new CaveNode(currNode, currNode.x - 1, currNode.y, targetX, targetY, terrain, (3 + terrain - currNode.terrain + currNode.equipment) % 3));
}
}
if (currNode.y > 0)
{
terrain = terrainGrid[currNode.y - 1][currNode.x];
if (currNode.equipment != (terrain + 2) % 3)
{
tryAddNode(new CaveNode(currNode, currNode.x, currNode.y - 1, targetX, targetY, terrain, currNode.equipment));
}
else
{
tryAddNode(new CaveNode(currNode, currNode.x, currNode.y - 1, targetX, targetY, terrain, (3 + terrain - currNode.terrain + currNode.equipment) % 3));
}
}
if (currNode.y < terrainGrid.Length - 1)
{
terrain = terrainGrid[currNode.y + 1][currNode.x];
if (currNode.equipment != (terrain + 2) % 3)
{
tryAddNode(new CaveNode(currNode, currNode.x, currNode.y + 1, targetX, targetY, terrain, currNode.equipment));
}
else
{
tryAddNode(new CaveNode(currNode, currNode.x, currNode.y + 1, targetX, targetY, terrain, (3 + terrain - currNode.terrain + currNode.equipment) % 3));
}
}
if (currNode.x < terrainGrid[currNode.y].Length - 1)
{
terrain = terrainGrid[currNode.y][currNode.x + 1];
if (currNode.equipment != (terrain + 2) % 3)
{
tryAddNode(new CaveNode(currNode, currNode.x + 1, currNode.y, targetX, targetY, terrain, currNode.equipment));
}
else
{
tryAddNode(new CaveNode(currNode, currNode.x + 1, currNode.y, targetX, targetY, terrain, (3 + terrain - currNode.terrain + currNode.equipment) % 3));
}
}
}
}
}
