Advent of Code 2020-01 with R & JavaScript
Solving Advent of Code 2020-01 with R and JavaScript.
[Disclaimer] Obviously, this post contains a big spoiler about Advent of Code, as it gives solutions for solving day 1.
[Disclaimer bis] I’m no JavaScript expert so this might not be the perfect solution. TBH, that’s also the case for the R solution.
About the JavaScript code
The JavaScript code has been written in the same RMarkdown as the R
code. It runs thanks to the {bubble}
package:
https://github.com/ColinFay/bubble
Instructions
-
Combine all the possible duos and trios of the input numbers
-
Locate the combination that equals 2020
-
Multiply the numbers from this combination to get the puzzle answer
Find the complete instructions at: https://adventofcode.com/2020/day/1.
R solution
Part one
# Read
ipt <- read.delim( "2020-01-aoc.txt", header = FALSE )
library(dplyr, warn.conflicts = FALSE)
# Creating all the combinations
tidystringdist::tidy_comb_all(ipt$V1) %>%
# Adding them together
mutate(sum = V1 + V2) %>%
# keeping only the one that equals 2020
filter(sum == 2020) %>%
# Multiplying it
mutate(res = V1 * V2) %>%
# Getting the answer
pull(res)
## [1] 445536
Part two
# Creating all the combinations
combn(
ipt$V1,
3
) %>%
# Transposing the matrix and turning it to a tibble
t() %>%
as_tibble() %>%
# Same old song as step 1
mutate(sum = V1 + V2 + V3) %>%
filter(sum == 2020) %>%
mutate(res = V1 * V2 * V3) %>%
pull(res)
## [1] 138688160
JS solution
Part one & Two
// Reading the file and converting it to int
const fs = require('fs')
var ipt = fs.readFileSync("2020-01-aoc.txt", 'utf8').split("\n").filter(x => x.length != 0);
ipt = ipt.map(x => parseInt(x));
// Doing the combn
var ipt2 = ipt;
var comb = ipt.flatMap(i => ipt2.map(j => [i, j]))
// Getting the 2020
var twentytwenty = comb.filter(x => (x[0] + x[1]) === 2020)
// Solution
twentytwenty.reduce(y => y[0] * y[1])
## 445536
// Same with three
var ipt3 = ipt;
var comb2 = ipt.flatMap(i => ipt2.flatMap(j => ipt3.map(k => [i, j, k])));
// Doing the computation
var twentytwenty2 = comb2.filter(x => (x[0] + x[1] + x[2]) === 2020)
// Solution
twentytwenty2.map(y => y[0] * y[1] * y[2])[0]
## 138688160
What do you think?