Day 10: Part1 & Part2 done

Author: tobigrimm

day10/day10.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+import sys
+import re
+from itertools import islice, permutations
+from collections import Counter, defaultdict
+from typing import Any, List, Iterator, Generator
+
+# from ..tools import sliding_window
+
+
+def window(seq: Iterator[Any], n: int = 2) -> Generator[Any, None, None]:
+    "Returns a sliding window (of width n) over data from the iterable"
+    "   s -> (s0,s1,...s[n-1]), (s1,s2,...,sn), ...                   "
+    "taken from https://docs.python.org/release/2.3.5/lib/itertools-example.html"
+    it = iter(seq)
+    result = tuple(islice(it, n))
+    if len(result) == n:
+        yield result
+    for elem in it:
+        result = result[1:] + (elem,)
+        yield result
+
+
+def calculate_diffs(inlist) -> int:
+    result = Counter()
+    jolt = 0
+    dist = 0
+    for i in inlist:
+    
+        diff = i - jolt
+        if diff == 1:
+            dist+=1
+            result[diff]+=1
+        jolt = i
+
+    # add final 3 jolt jump
+    result[3]+=1
+    return int(result[1]*result[3])
+
+def get_variants(inlist) -> int:
+    # defaultdict from int will default to 0 if an entry does not exist
+    ways = defaultdict(int)
+    ways[0] = 1
+    # skip the leading 0, as that is always reached 
+    # and already account for above :)
+    for i in inlist[1:]:
+        ways[i] = ways[i-1]+ways[i-2]+ways[i-3]
+    return ways[max(inlist)]
+
+
+if __name__ == "__main__":
+    with open(sys.argv[1], "r") as infile:
+        # add initial 0 as input jolt
+        jolts = [0]
+        for nextline in infile:
+            jolt = int(nextline.strip())
+            jolts.append(jolt)
+    jolts = sorted(jolts)
+    part1 = calculate_diffs(jolts)
+    print("Part1: ", part1)
+    print("Part2: ", get_variants(jolts))