From d1403d0e2567f3b580b6b26d302dd324fac1a2c9 Mon Sep 17 00:00:00 2001
From: Lachlan Meyer <lachlanmeyer@gmail.com>
Date: Mon, 16 Dec 2024 18:08:25 +1100
Subject: [PATCH] 15-2

---
 2024/15/15-2.py             | 111 ++++++++++++++++++++++++++++++++++++
 2024/15/testinputsmall2.txt |   9 +++
 2 files changed, 120 insertions(+)
 create mode 100644 2024/15/15-2.py
 create mode 100644 2024/15/testinputsmall2.txt

diff --git a/2024/15/15-2.py b/2024/15/15-2.py
new file mode 100644
index 0000000..44419f1
--- /dev/null
+++ b/2024/15/15-2.py
@@ -0,0 +1,111 @@
+import functools
+
+map = {}
+moves = []
+currentPosition = startPosition = (-1, -1)
+width = height = 0
+total = 0
+
+def calcGpsCoords():
+    global total
+    for i in range(height):
+        for j in range(width):
+            if map[i,j] == '[':
+                total += i * 100 + j
+
+def printMap():
+    output = ""
+    for i in range(height):
+        line = ""
+        for j in range(width):
+            line += map[i,j]
+        output += line + "\n"
+    print(output)
+
+@functools.cache
+def getDirectionCoords(direction):
+    match direction:
+        case '^':
+            return 0, -1
+        case 'v':
+            return 0, 1
+        case '<':
+            return -1, 0
+        case '>':
+            return 1, 0
+        case _:
+            raise Exception("bruh")
+
+def tryMoveInDirection(startX, startY, direction, allowMove = False):
+    global currentPosition
+    # see if there's something in front, try move that (recursively)
+    # if there's a wall in front, return False
+    # move up if all clear, return True
+
+    char = map[startY, startX]
+
+    dirX, dirY = getDirectionCoords(direction)
+    nextX, nextY = startX + dirX, startY + dirY
+    nextSpot = map[nextY, nextX]
+    if nextSpot == '#':
+        return False
+
+    if nextSpot == '[':
+        # it's the left of a box, try move it and the right side and all subsequent boxes
+        if dirX == 0:
+            if not (tryMoveInDirection(nextX, nextY, direction, allowMove) and tryMoveInDirection(nextX+1, nextY, direction, allowMove)):
+                return False
+        elif not tryMoveInDirection(nextX, nextY, direction, allowMove):
+            return False
+    elif nextSpot == ']':
+        # it's the right of a box, try move it and the left side and all subsequent boxes
+        if dirX == 0:
+            if not (tryMoveInDirection(nextX, nextY, direction, allowMove) and tryMoveInDirection(nextX-1, nextY, direction, allowMove)):
+                return False
+        elif not tryMoveInDirection(nextX, nextY, direction, allowMove):
+            return False
+        
+    # the robot and box(es) could move without hitting a wall
+    if allowMove:
+        map[nextY, nextX] = char
+        map[startY, startX] = '.'
+        currentPosition = (nextX, nextY)
+    return True
+
+
+
+with open("2024/15/input.txt") as f: 
+    writingMap = True
+    for i, line in enumerate(f):
+        line = line.strip()
+        if i == 0:
+            height = int(len(line))
+            width = height * 2
+
+        if len(line) == 0:
+            writingMap = False
+        length = len(line)
+        for j, char in enumerate(line):
+            if writingMap:
+                if char == '@':
+                    currentPosition = startPosition = (j*2, i)
+                    map[i,j*2] = '@'
+                    map[i,j*2+1] = '.'
+                elif char == 'O':
+                    map[i,j*2] = '['
+                    map[i,j*2+1] = ']'
+                else:
+                    map[i,j*2] = char
+                    map[i,j*2+1] = char
+
+            else:
+                moves.append(char)
+
+    printMap()
+    
+    for direction in moves:
+        if tryMoveInDirection(currentPosition[0], currentPosition[1], direction):
+            tryMoveInDirection(currentPosition[0], currentPosition[1], direction, True)
+
+    calcGpsCoords()
+    print(total)
\ No newline at end of file
diff --git a/2024/15/testinputsmall2.txt b/2024/15/testinputsmall2.txt
new file mode 100644
index 0000000..dfe6a69
--- /dev/null
+++ b/2024/15/testinputsmall2.txt
@@ -0,0 +1,9 @@
+#######
+#...#.#
+#.....#
+#..OO@#
+#..O..#
+#.....#
+#######
+
+<vv<<^^<<^^
\ No newline at end of file