Solve 2021 day 12-14

2021/d13.py

@@ -0,0 +1,51 @@
+from lib import get_data
+from lib import ints
+
+data = get_data(__file__).strip()
+
+
+def print_from_xy(xs):
+    x_min = min(v[0] for v in xs)
+    x_max = max(v[0] for v in xs)
+    y_min = min(v[1] for v in xs)
+    y_max = max(v[1] for v in xs)
+    for y in range(y_min, y_max + 1):
+        row = ""
+        for x in range(x_min, x_max + 1):
+            if (x, y) in xs:
+                row += "#"
+            else:
+                row += " "
+        print(row)
+
+
+p1, p2 = data.split("\n\n")
+xs = set([tuple(ints(line)) for line in p1.splitlines()])
+
+folds = []
+for line in p2.splitlines():
+    d = "x" if "x=" in line else "y"
+    (n,) = ints(line)
+    folds.append((d, n))
+
+
+first = None
+for d, n in folds:
+    if d == "x":
+        to_move = [(x, y) for (x, y) in xs if x > n]
+        for x, y in to_move:
+            xs.remove((x, y))
+            new_x = n - (x - n)
+            xs.add((new_x, y))
+    elif d == "y":
+        to_move = [(x, y) for (x, y) in xs if y > n]
+        for x, y in to_move:
+            xs.remove((x, y))
+            new_y = n - (y - n)
+            xs.add((x, new_y))
+    else:
+        assert False
+    first = first or len(xs)
+
+print(first)
+print_from_xy(xs)