Advent of code

Some tips to solve https://adventofcode.com/.

Get input.txt

A Makefile rule:

YEAR=2024

input.txt: ../cookie.txt
	DAY=$$(basename $$(pwd)); wget -O $@ --header="Cookie: $$(cat ../cookie.txt)" https://adventofcode.com/$(YEAR)/day/$${DAY##day}/input

Get content of ../cookie.txt (collect using Firefox developers / storage panel):

session=aaaaaaaaaaaaaabbbbbbbbbbbbbbcccccccccccccddddddddddde1111111222222222333333333444444444555555555555

I/O

Read a list of numbers

Code	Output
print("Input:") for line in open(INPUT): print(line.strip())	Input: 3 4 4 3 2 5 1 3 3 9 3 3
F=[] # Flat for line in open(INPUT): numbers = list(map(int,line.split())) F.extend(numbers) print(f"{F}")	[3, 4, 4, 3, 2, 5, 1, 3, 3, 9, 3, 3]
L=[] # List for line in open(INPUT): numbers = list(map(int,line.split())) L.append(numbers) print(f"{L}")	[[3, 4], [4, 3], [2, 5], [1, 3], [3, 9], [3, 3]]

Read a list of miscellaneous data

See also:

• Python - regex module

Code	Output
# Input: # ------ # ABC 3 FGH 4 # IZP 4 XYZ 3 # KIJ 2 FGH 5 # ABC 1 TYE 3 # FIS 3 FGH 9 # ABC 3 FGH 3 INPUT2='small2.txt' L = [] for line in open(INPUT2): matches = re.findall(r'([A-Z]+|\d+)',line) L.append(matches) print(f"{L}")	[['ABC', '3', 'FGH', '4'], ['IZP', '4', 'XYZ', '3'], ['KIJ', '2', 'FGH', '5'], ['ABC', '1', 'TYE', '3'], ['FIS', '3', 'FGH', '9'], ['ABC', '3', 'FGH', '3']]
# Input: # Button A: X+27, Y+18 # Button B: X+17, Y+44 # Prize: X=8105, Y=9698 with open(INPUT) as f: while True: x_a,y_a=list(map(int,re.findall(r'Button A: X\+(\d+), Y\+(\d+)',f.readline())[0])) x_b,y_b=list(map(int,re.findall(r'Button B: X\+(\d+), Y\+(\d+)',f.readline())[0])) X,Y=list(map(int,re.findall(r'Prize: X=(\d+), Y=(\d+)',f.readline())[0])) print(x_a,y_a) print(x_b,y_b) print(X,Y) if not f.readline(): break	27 18 17 44 8105 9698
# Input: # 5,4 # 4,2 # 4,5 # 3,0 # 2,1 # Read the whole thing and extract only numbers, then reorg... bytes = list(map(int,re.findall(r'\d+',open(INPUT).read()))) bytes = [(bytes[i],bytes[i+1]) for i in range(0,len(bytes),2)] print(bytes)	[(5, 4), (4, 2), (4, 5), (3, 0), (2, 1)]