Advent of Code: 2024 Day 4 / Jo Wood

Jo Wood

Professor of Visual Analytics interested in design, geovisualization, visual storytelling and computational thinking.

Workspace

Public

Ξ🎄Advent of Code 2024

Edited

Dec 4

Paused

function parse(input) {

return input.split("\n").map((row) => row.split(""));

}

dirs8 = [

[-1, -1],

[0, -1],

[1, -1],

[-1, 0],

[1, 0],

[-1, 1],

[0, 1],

[1, 1]

]

function getStr(grid, row, col, dirs, len, offset = 0) {

return dirs

.map(([dr, dc]) => {

const str = d3

.range(len)

.map(

(i) => grid[row + (i - offset) * dr]?.[col + (i - offset) * dc] ?? ""

)

.join("");

return str.length === len ? str : "";

})

.filter((str) => str !== "");

}

function part1(input) {

const grid = parse(input);

const wordCount = (r, c, chr) =>

chr === "X"

? getStr(grid, r, c, dirs8, 4).filter((d) => d === "XMAS").length

: 0;

return d3.sum(AOC.gMapWithLocation(wordCount, grid).flat());

}

dirs4 = [

[-1, -1],

[1, -1],

[-1, 1],

[1, 1]

]

function part2(input) {

const grid = parse(input);

const cross = (r, c, chr) =>

chr === "A" &&

getStr(grid, r, c, dirs4, 3, 1).filter((d) => d === "MAS").length === 2;

return d3.sum(AOC.gMapWithLocation(cross, grid).flat());

}

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