Advent of Code 2022 Day 4

— Day 4: Camp Cleanup —

The elves need to do some cleaning, and have been assigned sections of the camp.

In how many assignment pairs does one range fully contain the other?

with open('data-2022-04.txt', 'r') as f:
    inp = f.read().splitlines()

There is some preparation required

task1 = [x.split(',') for x in inp]
task2 = [x[0].split('-') + x[1].split('-') for x in task1]
task3 = [list(map(int, x)) for x in task2]

Now, do we have any overlapping ranges? Probably.

def within(lst):
    # first pair within second
    if lst[0] >= lst[2] and lst[1] <= lst[3]:
        return True
    # second pair within first
    elif lst[2] >= lst[0] and lst[3] <= lst[1]:
        return True
    else:
        return False

Sweet, let’s check the list

num1 = [within(x) for x in task3]

sum(num1)

# 571

571

— Part Two —

Actually, we’re just looking for any overlap, rather than one within the other.

In how many assignment pairs do the ranges overlap?

def overlap(lst):
    return lst[1] < lst[2] or lst[3] < lst[0]

And use this on our list

num2 = [overlap(x) for x in task3]  

1000 - sum(num2)

# 917

917