init

2023/day10/p1/main.py

@@ -0,0 +1,118 @@
+import math
+INPUT_FILE = "input.text"
+
+
+class Point:
+    x: int
+    y: int
+
+    def __init__(self, x: int , y: int):
+        self.x = x
+        self.y = y
+
+    def add(self, other):
+        return Point(self.x + other.x, self.y + other.y)
+
+    def __str__(self) -> str:
+        return f'P({self.x}, {self.y})'
+
+    def __eq__(self, other) -> bool:
+        return self.x == other.x and self.y == other.y
+
+class PipeMap:
+    pipe_map: list[str]
+    start_position: Point
+    bounds: Point
+
+    def __init__(self, map_path: str):
+
+        with open(map_path, 'r') as file:
+            self.pipe_map = file.readlines()
+
+        for i in range(0, len(self.pipe_map)):
+            self.pipe_map[i] = self.pipe_map[i][:-1]
+
+        max_y = len(self.pipe_map)
+        for row in range(0, max_y):
+            max_x = len(self.pipe_map[row])
+            col = self.pipe_map[row].find('S')
+
+            if col != -1:
+                self.bounds = Point(max_x, max_y)
+                self.start_position = Point(row, col)
+
+    def in_bounds(self, p: Point) -> bool:
+        return (p.y < self.bounds.x and p.x < self.bounds.y and p.x >= 0 and p.y >= 0)
+
+
+directions = {
+    8 : Point(-1, 0),
+    9 : Point(-1, 1),
+    6 : Point(0, 1),
+    3 : Point(1, 1),
+    2 : Point(1, 0),
+    1 : Point(1, -1),
+    4 : Point(0, -1),
+    7 : Point(-1, -1)
+}
+
+pipe_directions = {
+    '|' : [Point(-1, 0), Point(1, 0)],
+    '-' : [Point(0, -1), Point(0, 1)],
+    'L' : [Point(-1, 0), Point(0, 1)],
+    'J' : [Point(-1, 0), Point(0, -1)],
+    '7' : [Point(0, -1), Point(1, 0)],
+    'F' : [Point(0, 1), Point(1, 0)],
+    '.' : [],
+    'S' : True
+}
+
+def main():
+
+    pipe_map = PipeMap(INPUT_FILE)
+
+    # Check around start
+    next_directions = None
+    current_pos: Point = pipe_map.start_position
+    last_pos: Point = current_pos
+
+    for d in directions:
+        new_pos = pipe_map.start_position.add(directions[d])
+
+        if pipe_map.in_bounds(new_pos):
+            if char := pipe_directions[pipe_map.pipe_map[new_pos.x][new_pos.y]]:
+
+                # Check if this pipe connects to start somehow
+                good = False
+                for d2 in char:
+                    if new_pos.add(d2) == current_pos:
+                        good = True
+                        break
+
+                if good:
+                    current_pos = new_pos
+                    next_directions = char
+                    break
+
+    steps = 1 # Because current pos isn't at start rn
+    while current_pos != pipe_map.start_position:
+
+        for direction in next_directions:
+            potential_pos: Point = current_pos.add(direction)
+            potential_directions: list[Point] = pipe_directions[pipe_map.pipe_map[potential_pos.x][potential_pos.y]]
+
+            if pipe_map.in_bounds(potential_pos) and potential_pos != last_pos and potential_directions:
+                last_pos = current_pos
+                current_pos = potential_pos
+                next_directions = potential_directions
+                steps += 1
+                break
+
+
+    print(f'Loop finished, start found in {steps} steps')
+    print(f'Critter is at {math.ceil(steps/2)}')
+
+
+
+if __name__ == '__main__':
+    main()