Solve a couple of 2017 problems.

2017/d11.py

@@ -0,0 +1,52 @@
+from lib import add2
+from math import ceil
+
+
+DIR = {
+    "n": (-2, 0),
+    "s": (2, 0),
+    "e": (0, 1),
+    "w": (0, -1),
+    "ne": (-1, 1),
+    "nw": (-1, -1),
+    "se": (1, 1),
+    "sw": (1, -1),
+}
+
+
+def steps_to_zero(pos: tuple[int, int]):
+    c = list(map(abs, pos))
+    steps = c[1]
+    c[0] -= c[1]
+    if c[0] > 0:
+        steps += ceil(c[0] / 2)
+    return steps
+
+
+def part_1(data):
+    c = (0, 0)
+    for d in data.split(","):
+        c = add2(c, DIR[d])
+    return steps_to_zero(c)
+
+
+def part_2(data):
+    c = (0, 0)
+    steps_max = 0
+    for d in data.split(","):
+        c = add2(c, DIR[d])
+        steps_max = max(steps_to_zero(c), steps_max)
+    return steps_max
+
+
+def main():
+    data = open(0).read().strip()
+    print(part_1(data))
+    print(part_2(data))
+    assert part_1("ne,ne,ne") == 3
+    assert part_1("ne,ne,sw,sw") == 0
+    assert part_1("ne,ne,s,s") == 2
+    assert part_1("se,sw,se,sw,sw") == 3
+
+if __name__ == "__main__":
+    main()