day4 part 2

day4/README.md

@@ -54,8 +54,26 @@ numbers. Visually, these pairs of section assignments look like this:
 ```
 
 Some pairs have noticed that one of their assignments **fully contains** the other. For example, `2-8` fully contains
-`3-7`, and `6-6` is fully contained by `4-6`. In pairs where one assignment fully contains the other, one Elf in the pair
+`3-7`, and `6-6` is fully contained by `4-6`. In pairs where one assignment fully contains the other, one Elf in the
+pair
 would be exclusively cleaning sections their partner will already be cleaning, so these seem like the most in need of
 reconsideration. In this example, there are **2** such pairs.
 
 **In how many assignment pairs does one range fully contain the other?**
+
+## Part Two
+
+It seems like there is still quite a bit of duplicate work planned. Instead, the Elves would like to know the number of
+pairs that **overlap at all**.
+
+In the above example, the first two pairs (`2-4,6-8` and `2-3,4-5`) don't overlap, while the remaining four
+pairs (`5-7,7-9`, `2-8,3-7`, `6-6,4-6`, and `2-6,4-8`) do overlap:
+
+- `5-7,7-9` overlaps in a single section, `7`.
+- `2-8,3-7` overlaps all the sections `3` through `7`.
+- `6-6,4-6` overlaps in a single section, `6`.
+- `2-6,4-8` overlaps in sections `4`, `5`, and `6`.
+
+So, in this example, the number of overlapping assignment pairs is `4`.
+
+**In how many assignment pairs do the ranges overlap?**

day4/main.py

@@ -1,3 +1,5 @@
+from typing import Callable, Iterable
+
 from common.file import read_data
 
 test_dataset = [
@@ -11,20 +13,22 @@ test_dataset = [
 
 
 def find_overlapping_assignments_1(data: list[str]) -> int:
-    # iterate over  the data, for each line
-    counter = 0
-    for line in data:
-        # split the ','
-        a, b = line.strip().split(",")
-        start_a, end_a = [int(x) for x in a.split("-")]
-        int_a = range(start_a, end_a + 1)
-        start_b, end_b = [int(x) for x in b.split("-")]
-        int_b = range(start_b, end_b + 1)
-        # if 1 interval in the other increment the counter
-        if all(x in int_b for x in int_a) or all(x in int_a for x in int_b):
-            counter += 1
-    # return the counter
-    return counter
+    return sum(process(line, all) for line in data)
+
+
+def find_overlapping_assignments_2(data: list[str]) -> int:
+    return sum(process(line, any) for line in data)
+
+
+def process(line: str, func: Callable[[Iterable], bool]) -> int:
+    a, b = line.strip().split(",")
+
+    start_a, end_a = [int(x) for x in a.split("-")]
+    int_a = range(start_a, end_a + 1)
+    start_b, end_b = [int(x) for x in b.split("-")]
+    int_b = range(start_b, end_b + 1)
+
+    return int(func(x in int_b for x in int_a) or func(x in int_a for x in int_b))
 
 
 if __name__ == "__main__":
@@ -32,6 +36,6 @@ if __name__ == "__main__":
 
     res = find_overlapping_assignments_1(dataset)
     assert res == 2, f"{res} is not the right value"
-    #
-    # res = priority_shared_items_sum_2(dataset)
-    # assert res == 70, f"{res} is not the right value"
+
+    res = find_overlapping_assignments_2(dataset)
+    assert res == 4, f"{res} is not the right value"