Day 23

day23/input.txt

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+952316487

day23/part1.py

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+#!/usr/bin/env python3
+from functools import reduce
+from tqdm import tqdm
+
+num = [list(map(int, (char for char in x.strip()))) for x in open("input.txt")][0]
+
+for _ in tqdm(range(100)):
+    destination = num[0]
+    while True:
+        destination -= 1
+        if destination == 0:
+            destination = 9
+        if not destination in num[1:4]:
+            break
+    pos = num.index(destination)
+    num = num[4:pos+1] + num[1:4] + num[pos+1:] + num[0:1]
+
+pos = num.index(1)
+print(reduce(lambda a, b: 10*a+b, num[pos+1:] + num[:pos], 0))

day23/part2.py

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+#!/usr/bin/env python3
+from tqdm import tqdm
+
+
+class Node:
+    value = None
+    next = None
+
+    def __init__(self, value, next):
+        self.value = value
+        self.next = next
+
+
+num = [list(map(int, (char for char in x.strip()))) for x in open("input.txt")][0]
+num = num + list(range(len(num)+1, 1000000+1))
+MAX = len(num)
+
+nodes = dict()
+nodes[num[-1]] = curr = last = Node(num[-1], None)
+for n in num[-2::-1]:
+    nodes[n] = curr = Node(n, curr)
+last.next = curr
+
+for _ in tqdm(range(10000000)):
+    pickups = []
+    lp = curr
+    for j in range(3):
+        lp = lp.next
+        pickups.append(lp.value)
+    ap = lp.next
+
+    destination = curr.value
+    while True:
+        destination -= 1
+        if destination == 0:
+            destination = MAX
+        if destination not in pickups:
+            break
+    dst = nodes[destination]
+    lp.next = dst.next
+    dst.next = curr.next
+    curr.next = ap
+    curr = curr.next
+
+while curr.value != 1:
+    curr = curr.next
+curr = curr.next
+res = curr.value
+curr = curr.next
+res *= curr.value
+
+print(res)