12-1

2024/12/12-1.py

@@ -1,8 +1,93 @@
-width = 0
+width = height = 0
 map = {}
 
-with open("2024/12/testinput.txt") as f:
+def printMap():
+    output = ""
+    for i in range(height):
+        line = ""
+        for j in range(width):
+            line += map[i,j]
+        output += line + "\n"
+    print(output)
+
+def findNeighbours(node):
+    x, y = node
+    nodes = set()
+    directions = [(1, 0), (0, 1), (-1, 0), (0, -1)]
+    for direction in directions:
+        dirX, dirY = direction
+        neighbour = (x + dirX, y + dirY)
+        if neighbour in map:
+            nodes.add(neighbour)
+    return nodes
+
+def findFences(region):
+    totalFences = 0
+    for node in region:
+        neighbours = findNeighbours(node)
+        fences = 4 - len(neighbours)
+        for candidate in neighbours:
+            if candidate not in region:
+                # there's a fence between the candidate
+                fences += 1
+
+        totalFences += fences
+    return totalFences
+
+def getRegion(node):
+    region = set() # set is like dict but I don't have to do that stupid (x,y): True thing I was doing
+    checkedNodes = set()
+    # do BFS or something
+    uncheckedNeighbours = [node]
+    while len(uncheckedNeighbours) != 0:
+        node = uncheckedNeighbours[0]
+        region.add(node)
+        checkedNodes.add(node)
+        # get neighbours
+        # add them to list if they have the same character
+
+        neighbourCandidates = findNeighbours(node)
+        unvisitedNeighbours = [neighbour for neighbour in neighbourCandidates if (map[neighbour] == map[node] and neighbour not in checkedNodes and neighbour not in uncheckedNeighbours)]
+        uncheckedNeighbours += unvisitedNeighbours
+        del uncheckedNeighbours[0]
+
+    return region
+
+with open("2024/12/input.txt") as f:
     for i, line in enumerate(f):
-        width = i + 1;
+        line = line.strip()
+        if i == 0:
+            width = height = int(len(line))
+        for j, char in enumerate(line):
+            map[i,j] = char
+
+printMap()
+
+# ideas
+# don't actually put fences up, it'll be a nightmare
+# for each area, recursively crawl across a spot for area, add them to a 2D list
+# find orthogonally adjacent neighbours for each of these spots
+# fencesAtSpot = 4 - neighbours
+# pray.
+
+visitedNodes = set()
+regions = []
+totalCost = 0
+
+for i in range(height):
+    for j in range(width):
+        node = (i, j)
+        if node not in visitedNodes:
+            # region finding
+            newRegion = getRegion(node)
+            regions.append(newRegion)
+            visitedNodes |= newRegion
+
+            # costs
+            area = len(newRegion)
+            perimeter = findFences(newRegion)
+            cost = area * perimeter
+            totalCost += cost
+            print(f'{map[list(newRegion)[0]]}: {cost}')
 
-        
+print(totalCost)

2024/12/testinput3.txt

@@ -0,0 +1,5 @@
+OOOOO
+OXOXO
+OOOOO
+OXOXO
+OOOOO