10

solutions/10/README.md

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+# 10
+
+The first one is really easy. Just sort, make the diff and count.
+
+<details>
+  <summary>Solutions</summary>
+  <ol>
+    <li>2475</li>
+    <li>442136281481216</li>
+  </ol>
+</details>

solutions/10/python/main.py

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+from os.path import join, dirname
+from typing import List, Optional, Set, Tuple
+from itertools import combinations, count
+from math import floor, prod
+
+
+def parse(s: str) -> List[int]:
+    numbers: List[int] = sorted(map(int, s.strip().split('\n')))
+    numbers.insert(0, 0)  # The wall
+    numbers.append(numbers[-1] + 3)  # Phone itself
+    return numbers
+
+
+def diff(l: List[int]) -> List[int]:
+    return [
+        l[x] - l[x-1]
+        for x in range(1, len(l))
+    ]
+
+
+def calc(d: List[int]) -> int:
+    one = d.count(1)
+    three = d.count(3)
+    return one * three
+
+
+def find_valid_permutations(d: List[int]) -> int:
+    i = 0
+    l = len(d)
+    slices: List[int] = []
+    while i < l:
+        if d[i] != 3:
+            try:
+                n = d.index(3, i + 1)  # Find the next three
+                diff = n - i
+                if diff > 1:
+                    slices.append(diff)
+                    i = n
+                    continue
+            except:
+                pass
+        i += 1
+    return prod([
+        2**(s-1) - floor(s/4)
+        for s in slices
+    ])
+
+
+data = join(dirname(__file__), '../data.txt')
+with open(data) as f:
+    numbers: List[int] = parse(f.read())
+    d = diff(numbers)
+    print(calc(d))
+    print(find_valid_permutations(d))