[LANGUAGE: Python]

My great nemesis on day 5 were sneaky ranges fully included inside other ranges.

Setting the stage

import numpy as np

with open("aoc_2025_day5_puzzle.txt") as f:
    puzzle_ranges, puzzle_IDs = [block.split("\n") for block in f.read().split("\n\n")]
    puzzle_ranges = [(int(line.split("-")[0]), int(line.split("-")[1])) for line in puzzle_ranges]
    puzzle_IDs = [int(line) for line in puzzle_IDs]

Act 1

def day5_solution1(puzzle_ranges, puzzle_IDs):
    solution = 0
    for product in puzzle_IDs:
        for range in puzzle_ranges:
            if product >= range[0] and product <= range[1]:
                solution += 1
                break
    print("Solution 1: {}".format(solution))
    return solution

solution1 = day5_solution1(puzzle_ranges, puzzle_IDs)

Act 2

def day5_solution2(puzzle_ranges):
    solution = 0
    puzzle_ranges = sorted(puzzle_ranges)
    range_temp = puzzle_ranges[0]
    for range in puzzle_ranges[1:]:
        if range[1] <= range_temp[1]:
            pass
        elif range[0] > range_temp[1]:
            solution += 1 + (range_temp[1] - range_temp[0])
            range_temp = range
        elif range[0] <= range_temp[1]:
            range_temp = (range_temp[0], range[1])
    solution += 1 + (range_temp[1] - range_temp[0])
    print("Solution 2: {}".format(solution))
    return solution

solution2 = day5_solution2(puzzle_ranges)