part 2

2022/13/part1.js

@@ -0,0 +1,46 @@
+import * as R from "remeda";
+
+import { readFile } from "../05/part1.js";
+
+const readInput = (...args) =>
+  R.pipe(
+    readFile(...args),
+    (lines) => lines.split("\n\n"),
+    R.compact, // remove last line
+    R.map(
+        block => block.split("\n").map( line => eval(line) )
+    )
+  );
+
+export const puzzleInput = readInput(import.meta.url, "input");
+export const sample = readInput(import.meta.url, "sample");
+
+export function isLessThan(x,y) {
+    if( [x,y].every(R.isNumber)  ) return x < y ? -1 : x == y ? 0 : 1;
+
+    if( [x,y].every(R.isArray)  ) {
+        for ( const [a,b]  of R.zip(x,y)) {
+            const res = isLessThan(a,b);
+            if(res !== 0) return res;
+        }
+        if( x.length === y.length ) return 0
+        return x.length < y.length ? -1 : 1;
+    }
+
+   return isLessThan(...[x,y].map( z => R.isNumber(z)? [z] : z ));
+}
+
+const passthru = (x) => (arg) => {
+    x(arg);
+    return arg;
+}
+
+export default R.createPipe(
+    R.map( ([x,y]) => isLessThan(x,y) ),
+    (results) => results.map(
+        (value,index) => ({ value, index: index+1 })
+    ),
+    R.filter( ({ value }) => value !== 1 ),
+    R.map( R.prop('index') ),
+    (results) => results.reduce((a,b) => a+b)
+);

2022/13/part2.js

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+import * as R from "remeda";
+import { isLessThan } from "./part1";
+
+const dividers = [[[2]],[[6]]];
+export default R.createPipe(
+    R.flatten,
+    R.concat(dividers),
+    (packets) => packets.sort(isLessThan),
+    packets => packets.map( (p,i) => ({ i: i+1, divider: dividers.includes(p) }) ),
+    R.filter( ({divider}) => divider ),
+    R.map(R.prop('i')),
+    (v) => v.reduce((a,b)=>a*b),
+);

2022/13/sample

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+[1,1,3,1,1]
+[1,1,5,1,1]
+
+[[1],[2,3,4]]
+[[1],4]
+
+[9]
+[[8,7,6]]
+
+[[4,4],4,4]
+[[4,4],4,4,4]
+
+[7,7,7,7]
+[7,7,7]
+
+[]
+[3]
+
+[[[]]]
+[[]]
+
+[1,[2,[3,[4,[5,6,7]]]],8,9]
+[1,[2,[3,[4,[5,6,0]]]],8,9]

2022/13/test.js

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+import { test, expect, describe } from "vitest";
+
+import { expectSolution } from "../01/main.js";
+import part1, { sample, puzzleInput, isLessThan } from "./part1.js";
+import part2 from "./part2.js";
+
+describe("part 1", () => {
+    test( "readInput", () => {
+        expect(sample[0][0]).toEqual([1,1,3,1,1]);
+
+    });
+    test( "lessThan", () => {
+        expect( isLessThan(1,2) ).toBe(-1);
+        expect( isLessThan(2,1) ).toBe(1);
+        expect( isLessThan(2,2) ).toBe(0);
+        expect( isLessThan(2,[1]) ).toBe(1);
+        expect( isLessThan([1],[2]) ).toBe(-1);
+    });
+  test("sample", () => {
+    expect(part1(sample)).toEqual(13);
+  });
+  test("solution", () => {
+    const r = part1(puzzleInput);
+    expect(r).toBeGreaterThan(435);
+    expect(r).toBeLessThan(10980);
+    expectSolution(r).toEqual(5806);
+  });
+});
+
+describe("part 2", () => {
+  test("sample", () => {
+    expect(part2(sample)).toEqual(140);
+  });
+  test("solution", () => {
+    expectSolution(part2(puzzleInput)).toEqual(23600);
+  });
+});