## DEV Community

Erik Guzman

Posted on • Updated on

# Today Objectives

β To have a good time as Christmas holiday time creeps up

β Start working on some Advent of Code challenges for fun today https://adventofcode.com/2019

## Stream Standup

This will be my second year trying to do any Advent of Code challenges so I am curious to see how far we can get today.

Since the last stream wrote a couple of articles posted to dev.to

Share Time:

# Notes

Advent of code challenge was fun. Made it through day one and day two of the problems.

Day one, part 2 ended up being a little more challenging since I was accidentally double count the initial fuel needed for the mass when calculation fuel needed for the added fuel mass.

Day two went really smoothly. It actually reminded me of my time in college, dealing with Assembly and Compiler class. Those classes heavily dealt with deal with memory space, instruction sets, and operation on the memory space. So when getting to part 2 it was really simple.

All the code isnt pretty but it gets the job code

``````Day 1:

# Day 1
## Part 1
def fuel_need(mass)
(mass/3).floor - 2
end

def part1
total_fuel_needs = 0
file = File.open("1-input.txt")

file.each do |mass|
total_fuel_needs  = total_fuel_needs + fuel_need(mass.to_i)
end
file.close

total_fuel_needs
end

total_fuel = part1
puts "Part 1: #{total_fuel}"
# 3150224

## Part 2
def calculate_fuels_need(fuel)
print fuel
total_fuel = 0
current_fuels_mass = fuel
loop do
current_fuels_mass = fuel_need(current_fuels_mass)
break if current_fuels_mass <= 0
print " + "
print current_fuels_mass
total_fuel = total_fuel + current_fuels_mass
end
puts ""
total_fuel
end

def part2
total_fuel_needs = 0
file = File.open("1-input.txt")

file.each do |module_mass|
fuel_for_mass = fuel_need(module_mass.to_i)
total_fuel_needs = calculate_fuels_need(fuel_for_mass)
end
file.close

total_fuel_needs
end

puts "Part 2: #{part2}"
``````
``````Day 2:

# Intcode: Command sep values
# opcodes: 1, 2, 99
# 99: exit
# Other codes mean error
# 1: Add operation - 1,indexV1,indexV2,storeIndex
# 1: Multi operation - 1,indexV1,indexV2,storeIndex
# 4 bit memory space
INSTRUCTION_SIZE = 4
EXIT_CODE = 99
MUTLI_CODE = 2

end

def multi!(instruction, memory)

end

def process(intcode)
pointer = 0

loop do
opcode = intcode[pointer]

instruction = intcode.slice(pointer, INSTRUCTION_SIZE)
elsif opcode == MUTLI_CODE
instruction = intcode.slice(pointer, INSTRUCTION_SIZE)
multi!(instruction, intcode)
elsif opcode == EXIT_CODE
break;
end

pointer += INSTRUCTION_SIZE
end

intcode
end

def part1
File.open("2-input.txt", "r") do |f|
f.each_line do |intcode|
intcodeArray = intcode.split(',')
intcodeArray.map!{ |v| v.to_i }
result = process(intcodeArray)
return result.join(',')
end
end
end

puts "Part1: #{part1}"

def part2(expectation)
File.open("2-input.txt", "r") do |f|
f.each_line do |intcode|
intcodeArray = intcode.split(',')
intcodeArray.map!{ |v| v.to_i }

for noun in 0..99 do
for verb in 0..99 do
new_memory_set = Array.new(intcodeArray)
new_memory_set[1] = noun
new_memory_set[2] = verb
result = process(new_memory_set)

return 100 * noun + verb if result[0] == expectation
end
end

end
end
end

puts "Part2: #{part2(19690720)}"
``````