Solve 2017 day 14 to 17.

2017/d17.py

@@ -0,0 +1,39 @@
+def part_1(data):
+    target = 2017
+    steps = int(data)
+    xs = [0]
+    i = 0
+    for n in range(1, target + 1):
+        i = (i + steps) % len(xs)
+        xs.insert(i + 1, n)
+        i += 1
+
+    for j in range(len(xs)):
+        if xs[j] == target:
+            print(xs[j + 1])
+            return
+
+
+def part_2(data, m=50_000_000):
+    steps = int(data)
+    len_xs = 1
+    last_zero = None
+    i = 0
+    for n in range(1, m + 1):
+        i = (i + steps) % len_xs
+        if i == 0:
+            last_zero = n
+        len_xs += 1
+        i += 1
+    return last_zero
+
+def main():
+    data = open(0).read().strip()
+    part_1(data)
+    assert part_2(data, 1000) == 531
+    assert part_2(data, 10000) == 2616
+    print(part_2(data))
+
+
+if __name__ == "__main__":
+    main()