Day 12

day12/part1.py

@@ -0,0 +1,36 @@
+import numpy as np
+
+lines = ((x[0], int(x[1:].strip())) for x in open("input.txt"))
+
+pos = np.array([0, 0], dtype=np.int32)
+drctn = np.array([1, 0], dtype=np.int32)
+targets = np.array([
+    [0, 1],
+    [1, 0],
+    [0, -1],
+    [-1, 0]
+], dtype=np.int32)
+target_str = "NESW"
+
+
+def direction(target):
+    return targets[target_str.index(target)]
+
+
+def rotate(current, amount):
+    angle = np.arctan2(current[1], current[0]) + np.pi / 180 * amount
+    amount = np.linalg.norm(current)
+    return np.array([np.rint(np.cos(angle) * amount), np.rint(np.sin(angle) * amount)], dtype=np.int32)
+
+
+for line in lines:
+    print(line)
+    if line[0] in target_str:
+        pos += direction(line[0]) * line[1]
+    elif line[0] in "LR":
+        drctn = rotate(drctn, -line[1] if line[0] == "R" else line[1])
+    else:
+        pos += drctn * line[1]
+    print(pos, drctn)
+
+print(sum(np.abs(pos)))