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Colin Fay
Colin Fay

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Advent of Code 2019-01 with R & JavaScript

Solving Advent of Code 2019-01 with R and JavaScript.

[Disclaimer] Obviously, this post contains a big spoiler about Adventof Code, as it gives solutions for solving day 1.

[Disclaimer bis] Iโ€™m no JavaScript expert so this might not be theperfect solution. TBH, thatโ€™s also the case for the R solution.

About the JavaScript code

The JavaScript code has been written in the same RMarkdown as the Rcode. It runs thanks to the {bubble} package:https://github.com/ColinFay/bubble

Instructions

Find the instructions at: https://adventofcode.com/2019/day/1

R solution

Part one

# Read ipt <- read.delim( "input1.txt", header = FALSE ) # Get the sum of each element, divided by 3, rounded down, and substracted 2 sum( floor( ipt$V1 / 3) - 2 ) ## [1] 3361299 
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Part two

Using a recursive function:https://en.wikipedia.org/wiki/Recursion_(computer_science)

floorish <- function(x, start = 0){ loc <- floor( x / 3) - 2 if (loc > 0){ start <- start + loc floorish(loc, start) } else { return(start) } } sum( purrr::map_dbl(ipt$V1, floorish) ) ## [1] 5039071 
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JS solution

Part one & Two

var fs = require('fs'); // Reading the file var res = fs.readFileSync("input1.txt", 'utf8').split("\n").filter(x => x.length != 0); // Turning to integer res = res.map(x => parseInt(x)); // Doing the floor of division less 2 var val = res.map(x => Math.floor(x / 3) - 2); // Suming var add = (x, y) => x + y; // Solution console.log( val.reduce(add) ); // Creating the recursive function function floorish(val, start = 0){ loc = Math.floor(val / 3) - 2; if (loc > 0){ start += loc; return floorish(loc, start); } else { return start; } } // Doing the computation console.log( res.map( x => floorish(x) ).reduce( add ) ); ## 3361299 ## 5039071 
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