diff options
| author | Marvin Borner | 2023-12-19 14:29:24 +0100 |
|---|---|---|
| committer | Marvin Borner | 2023-12-19 14:34:55 +0100 |
| commit | 05c842e23abe76e33e23fb4a0f1d71fcdf3d1db6 (patch) | |
| tree | 4999fb2e0093897d659c669f08b88dfd4b745c0c /2023/19 | |
| parent | a3820a8523c6e75c68c5eb3320baab2756e45544 (diff) | |
wtf
Diffstat (limited to '2023/19')
| -rw-r--r-- | 2023/19/solve.js | 37 |
1 files changed, 35 insertions, 2 deletions
diff --git a/2023/19/solve.js b/2023/19/solve.js index 4a50178..829e41f 100644 --- a/2023/19/solve.js +++ b/2023/19/solve.js @@ -1,6 +1,6 @@ const fs = require("fs"); let [workflows, parts] = fs.readFileSync("input", "utf8").trim().split("\n\n"); -workflows = workflows.split("\n").map((l) => [l.split("{")[0], l .split("{")[1] .slice(0, -1).split(",").map((w) => w.split(":"))]); +workflows = workflows.split("\n").map((l) => [l.split("{")[0], l.split("{")[1].slice(0, -1).split(",").map((w) => w.split(":"))]); parts = parts.split("\n").map((l) => l.slice(1, -1)); const findWorkflow = (name) => workflows.filter(([n, _]) => name == n)[0][1]; @@ -25,4 +25,37 @@ for (const part of parts) { } console.log(part1); -let part2 = 0 +const rec = (name, ranges) => { + if (name == "R") return 0; + if (name == "A") return Object.values(ranges).map(([lo, hi]) => Math.max(0, hi - lo - 1)).reduce((a, b) => a * b, 1); + + let res = 0; + const rules = findWorkflow(name); + for (const rule of rules) { + if (rule.length == 1) { + res += rec(rule[0], ranges); + } else { + const [v, cmp, ..._n] = rule[0]; + const n = +_n.join(""); + + let aah = structuredClone(ranges); + if (cmp == ">") { + const huh = Math.max(aah[v][0], n); + aah[v][0] = huh; + res += rec(rule[1], aah); + ranges[v][1] = huh + 1; + } else if (cmp == "<") { + const huh = Math.min(aah[v][1], n); + aah[v][1] = huh; + res += rec(rule[1], aah); + ranges[v][0] = huh - 1; + } + } + } + + return res; +}; + +console.log( + rec("in", { x: [0, 4001], m: [0, 4001], a: [0, 4001], s: [0, 4001] }), +); |