2020/3

toolkit.py

@@ -28,7 +28,7 @@ def read_image(text):
     for y, line in enumerate(text.splitlines()):
         for x, cell in enumerate(line):
             grid[complex(x, y)] = cell
-    return grid
+    return grid, x + 1, y + 1
 
 
 def shortest_path(start, end, move):

y2020/p03.py

@@ -0,0 +1,20 @@
+import sys
+from math import prod
+
+
+def slide(step):
+    dx, dy = step
+    seen, x, y = 0, 0, 0
+    while y + dy < height:
+        x += dx
+        y += dy
+        seen += grid[y][x % width] == '#'
+    return seen
+
+
+grid = sys.stdin.read().splitlines()
+height = len(grid)
+width = len(grid[0])
+
+print(slide((3, 1)))
+print(prod(map(slide, [(1, 1), (3, 1), (5, 1), (7, 1), (1, 2)])))