2023 day 6

puzzles/Y2023/D6/p1.py

@@ -0,0 +1,23 @@
+import re
+from typing import Any
+
+digits = re.compile("([0-9]+)")
+
+
+def puzzle(input: str) -> Any:
+    lines = [line.strip() for line in input.splitlines()]
+    times = [int(num) for num in re.findall(digits, lines[0])]
+    record_distances = [int(num) for num in re.findall(digits, lines[1])]
+    num_races = len(times)
+
+    total = 1
+    for race_index in range(num_races):
+        race_time = times[race_index]
+        race_record = record_distances[race_index]
+        winning_combinations = 0
+        for i in range(race_time + 1):
+            distance_travelled = i * (race_time - i)
+            if distance_travelled > race_record:
+                winning_combinations += 1
+        total *= winning_combinations
+    return total

puzzles/Y2023/D6/p2.py

@@ -0,0 +1,27 @@
+import re
+from typing import Any
+
+digits = re.compile("([0-9]+)")
+
+
+def puzzle(input: str) -> Any:
+    lines = [line.strip() for line in input.splitlines()]
+    time = int("".join(num for num in re.findall(digits, lines[0])))
+    record_distance = int("".join(num for num in re.findall(digits, lines[1])))
+
+    # iterate from start to find first value of i that wins a race
+    first = 0
+    for i in range(time + 1):
+        distance_travelled = i * (time - i)
+        if distance_travelled > record_distance:
+            first = i
+            break
+
+    # iterate from the end to find the last value of i that wins a race
+    last = 0
+    for i in range(time + 1, -1, -1):
+        distance_travelled = i * (time - i)
+        if distance_travelled > record_distance:
+            last = i
+            break
+    return last - first + 1