diff --git a/2022/15/part1.js b/2022/15/part1.js
new file mode 100644
index 0000000..a196927
--- /dev/null
+++ b/2022/15/part1.js
@@ -0,0 +1,83 @@
+import * as R from "remeda";
+
+import { passthru } from "../08/part1.js";
+import { readFile } from "../05/part1.js";
+
+import V from '@yanick/vyktor';
+import { createLogger } from "vite";
+
+const readInput = (...args) =>
+    R.pipe(
+        readFile(...args),
+        (lines) => lines.split("\n"),
+        R.compact, // remove last line
+        R.map(line => line.match(/x=-?.*?y=-?\d+/g).map(str =>
+            str.match(/-?\d+/g).map(x => parseInt(x))).map(
+                coords => V(coords)
+            )
+        ));
+
+export const puzzleInput = readInput(import.meta.url, "input");
+export const sample = readInput(import.meta.url, "sample");
+
+/** @returns [number,number][] */
+export const mergeRanges = ( ranges ) =>  {
+
+return    ranges.reduce( (accum,range) => {
+        if( accum.length === 0 ) return [ range ];
+        if( R.last( accum )[1] < range[0] ) {
+            accum.push(range);
+        }
+        else {
+            R.last(accum)[1] = Math.max( 
+                R.last(accum)[1], range[1]
+            )
+        }
+        return accum;
+    }, [] );
+}
+
+export const spy = passthru( x => console.log(x) );
+
+const entriesInRange = (targetLine,entries) => {
+
+    entries = R.uniqBy(entries.map(([_,beacon])=>beacon).filter( beacon => beacon?.y === targetLine ), (x) => x.toString());
+
+ return range => {
+        return entries.filter(
+            entry => (entry.x >= range[0]) && (entry.x <= range[1])
+        ).length
+    }
+};
+
+export const unbeaconAtLine = targetLine => entries => R.pipe(
+    entries,
+    R.map( ([x,y]) => [ x, x.manhattanDistance(y) ] ),
+        R.filter(
+e => (
+            ( e[0].y - e[1] <= targetLine) &&
+            ( e[0].y + e[1] >= targetLine) 
+        ) 
+        ),
+        R.map(
+            e => {
+                const l = e[1] - Math.abs(targetLine - e[0].y);
+
+                return [
+        e[0].x - l,
+        e[0].x + l ]
+             }
+        ),
+    spy,
+    (ranges) => 
+        ranges.sort( (a,b) => {
+            return (a[0] - b[0]) || (a[1]-b[1]);
+        } )
+    ,
+    spy,
+    mergeRanges,
+    spy,
+    R.sumBy( range => range[1] - range[0] + 1 - entriesInRange(targetLine,entries)(range) ) 
+    );
+
+export default unbeaconAtLine(2000000);
diff --git a/2022/15/part2.js b/2022/15/part2.js
new file mode 100644
index 0000000..543b6bf
--- /dev/null
+++ b/2022/15/part2.js
@@ -0,0 +1,63 @@
+import * as R from "remeda";
+import V from '@yanick/vyktor';
+
+import {
+    spy,
+mergeRanges
+} from './part1.js';
+
+const unbeaconAtLine = (max,targetLine,already) => entries => R.pipe(
+    entries,
+    R.map( ([x,y]) => [ x, x.manhattanDistance(y) ] ),
+        R.filter(
+e => (
+            ( e[0].y - e[1] <= targetLine) &&
+            ( e[0].y + e[1] >= targetLine) 
+        ) 
+        ),
+        R.map(
+            e => {
+                const l = e[1] - Math.abs(targetLine - e[0].y);
+
+                return [
+        e[0].x - l,
+        e[0].x + l ]
+             }
+        ),
+    //spy,
+    (ranges) => [
+        ...ranges, ...already.filter( v => v.y === targetLine ).map(
+            v => [ v.x,v.x ]
+        )
+    ],
+    (ranges) => 
+        ranges.sort( (a,b) => {
+            return (a[0] - b[0]) || (a[1]-b[1]);
+        } )
+    ,
+    // spy,
+    R.map(
+        range => [ Math.max(0,range[0]), Math.min(max,range[1])]
+    ),
+    mergeRanges,
+    // spy,
+    // R.sumBy( range => range[1] - range[0] + 1 - entriesInRange(targetLine,entries)(range) ) 
+    );
+
+export const findBeacon = max => entries => {
+
+    const already = entries.flat()
+
+    for (let y = 0; y <= max; y++) {
+        const ranges = unbeaconAtLine(max,y,already)(entries)
+        if( ranges.length > 1 ) {
+            return y + 4000000 * (ranges[0][1] +1);
+        }
+
+//        return 'bob';
+
+ //       return x * 4000000 + y;
+    }
+}
+
+export default findBeacon(4000000);
diff --git a/2022/15/sample b/2022/15/sample
new file mode 100644
index 0000000..a612424
--- /dev/null
+++ b/2022/15/sample
@@ -0,0 +1,14 @@
+Sensor at x=2, y=18: closest beacon is at x=-2, y=15
+Sensor at x=9, y=16: closest beacon is at x=10, y=16
+Sensor at x=13, y=2: closest beacon is at x=15, y=3
+Sensor at x=12, y=14: closest beacon is at x=10, y=16
+Sensor at x=10, y=20: closest beacon is at x=10, y=16
+Sensor at x=14, y=17: closest beacon is at x=10, y=16
+Sensor at x=8, y=7: closest beacon is at x=2, y=10
+Sensor at x=2, y=0: closest beacon is at x=2, y=10
+Sensor at x=0, y=11: closest beacon is at x=2, y=10
+Sensor at x=20, y=14: closest beacon is at x=25, y=17
+Sensor at x=17, y=20: closest beacon is at x=21, y=22
+Sensor at x=16, y=7: closest beacon is at x=15, y=3
+Sensor at x=14, y=3: closest beacon is at x=15, y=3
+Sensor at x=20, y=1: closest beacon is at x=15, y=3
diff --git a/2022/15/test.js b/2022/15/test.js
new file mode 100644
index 0000000..e53af8b
--- /dev/null
+++ b/2022/15/test.js
@@ -0,0 +1,29 @@
+import { test, expect, describe } from "vitest";
+
+import { expectSolution } from "../01/main.js";
+import part1, { sample, puzzleInput, unbeaconAtLine } from "./part1.js";
+import part2, { findBeacon } from "./part2.js";
+
+describe("part 1", () => {
+    test('readInput', () => {
+        expect(sample[0][0].toArray()).toEqual([2, 18]);
+    });
+
+    test('sample', () => {
+        expect(unbeaconAtLine(10)(sample)).toEqual(26);
+    });
+
+    test("solution", () => {
+        expectSolution(part1(puzzleInput)).toEqual(5525990);
+    });
+});
+
+describe("part 2", () => {
+    test('sample', () => {
+        expect(findBeacon(20)(sample)).toEqual(56000011);
+    });
+    test("solution", () => {
+        // 314 seconds!
+        expectSolution(part2(puzzleInput)).toEqual(11756174628223);
+    });
+});
diff --git a/2022/16/fast.js b/2022/16/fast.js
new file mode 100644
index 0000000..5357596
--- /dev/null
+++ b/2022/16/fast.js
@@ -0,0 +1,4 @@
+import part1, { sample, puzzleInput } from "./part1.js";
+import part2 from "./part2.js";
+
+console.log(part2(puzzleInput));
diff --git a/2022/16/part1.js b/2022/16/part1.js
new file mode 100644
index 0000000..859c0be
--- /dev/null
+++ b/2022/16/part1.js
@@ -0,0 +1,92 @@
+import * as R from "remeda";
+import u from "updeep";
+
+import Graph from 'graphology';
+import { bidirectional } from 'graphology-shortest-path';
+
+import { combinations, permutations } from "combinatorial-generators";
+
+import { readFile } from "../05/part1.js";
+
+const parseLine = (line) => {
+    const { groups } = line.match(/Valve (?<valve>..).*flow rate=(?<flow>\d+).*valves? (?<exits>.*)/);
+    return [groups.valve, {
+        exits: groups.exits.split(',').map(x => x.trim()),
+        flow: parseInt(groups.flow)
+    }]
+}
+const readInput = (...args) =>
+    R.pipe(
+        readFile(...args),
+        (lines) => lines.split("\n"),
+        R.compact, // remove last line
+        R.map(parseLine),
+        Object.fromEntries,
+    );
+
+export const puzzleInput = readInput(import.meta.url, "input");
+export const sample = readInput(import.meta.url, "sample");
+
+function finalSteam(tunnels, graph, minutesLeft, possibilities, location = 'AA', activeSteam = 0) {
+    //console.log(minutesLeft, totalSteam, itinary);
+
+    if (minutesLeft <= 0) return 0;
+
+    if (possibilities.length === 0) return minutesLeft * activeSteam;
+
+    let scores = [];
+
+    for ( const next of possibilities ) {
+        const path = bidirectional(graph, location, next);
+        
+    //console.log(path);
+
+    let time = path.length;
+    if (time >= minutesLeft) {
+            scores.push( minutesLeft * activeSteam );
+    }
+    else {
+        //console.log({totalSteam, time, activeSteam});
+        let ts = time * activeSteam;
+        let as = activeSteam + tunnels[next].flow;
+
+        scores.push(
+                ts + finalSteam(
+                    tunnels, graph, minutesLeft - time,
+                    possibilities.filter( x => x !== next ),
+                    next,
+                    as
+                )
+        )
+    }
+
+    }
+
+    return Math.max( ...scores );
+}
+
+export const buildGraph = tunnels => {
+    const graph = new Graph();
+    Object.keys(tunnels).forEach(x => graph.addNode(x));
+
+    Object.entries(tunnels).forEach(([location, { exits }]) => {
+        exits.forEach(exit => graph.addEdge(location, exit));
+    });
+
+
+    return graph;
+
+};
+
+export default (tunnels) => {
+
+    const possibilities = 
+        Object.keys(tunnels).filter(
+            k => tunnels[k].flow
+        );
+
+    const graph = buildGraph(tunnels);
+
+    return  finalSteam(tunnels, graph, 30, possibilities, 'AA', 0, 0)
+
+};
diff --git a/2022/16/part2.js b/2022/16/part2.js
new file mode 100644
index 0000000..1c649cb
--- /dev/null
+++ b/2022/16/part2.js
@@ -0,0 +1,86 @@
+import { bidirectional } from 'graphology-shortest-path';
+import * as R from "remeda";
+import u from 'updeep';
+
+import { buildGraph } from './part1.js';
+
+const findMaxSteam = (tunnels,graph, minutesLeft, unopened, opened, activeSteam, peeps ) => {
+
+    console.log({ unopened, activeSteam, minutesLeft});
+
+    let next = R.sortBy(peeps, R.prop('eta'));
+
+    if( next[0].eta > minutesLeft ) {
+        return minutesLeft * activeSteam;
+    }
+
+    const delta = next[0].eta;
+    const location = next[0].destination;
+
+    const base = delta * activeSteam;
+    minutesLeft -= delta;
+
+    activeSteam += tunnels[ next[0].destination ].flow;
+    opened = [ ...opened, next[0].destination ];
+
+    next = u.updateIn( '1.eta', eta => eta - delta, next );
+
+    const scores = [];
+
+
+
+
+    let nothing = true;
+    for ( const destination of unopened ) {
+        const path = bidirectional(graph, location, destination );
+
+        if( path.length > minutesLeft) {
+            continue;
+        }
+        nothing = false;
+
+        next = u.updateIn( '0', {
+            location,
+            eta: path.length,
+            destination 
+        },next);
+
+        scores.push( findMaxSteam(tunnels,graph,minutesLeft,
+            unopened.filter( x => x !== destination ),
+            opened, activeSteam, next
+        ) );
+    }
+
+    if( nothing ) {
+        next = u.updateIn( '0', {
+            location,
+            eta: 999,
+            destination: 'END',
+        },next);
+
+        scores.push( findMaxSteam(tunnels,graph,minutesLeft,
+            unopened,
+            opened, activeSteam, next
+        ) );
+    }
+
+    return base + Math.max( ...scores );
+
+
+}
+
+export default (tunnels) => {
+
+    const possibilities = 
+        Object.keys(tunnels).filter(
+            k => tunnels[k].flow
+        );
+
+    const graph = buildGraph(tunnels);
+
+    return  findMaxSteam(tunnels, graph, 26, possibilities,[],0, [
+        { destination: 'AA', eta: 0 },
+        { destination: 'AA', eta: 0 },
+    ])
+
+};
diff --git a/2022/16/sample b/2022/16/sample
new file mode 100644
index 0000000..9f30acc
--- /dev/null
+++ b/2022/16/sample
@@ -0,0 +1,10 @@
+Valve AA has flow rate=0; tunnels lead to valves DD, II, BB
+Valve BB has flow rate=13; tunnels lead to valves CC, AA
+Valve CC has flow rate=2; tunnels lead to valves DD, BB
+Valve DD has flow rate=20; tunnels lead to valves CC, AA, EE
+Valve EE has flow rate=3; tunnels lead to valves FF, DD
+Valve FF has flow rate=0; tunnels lead to valves EE, GG
+Valve GG has flow rate=0; tunnels lead to valves FF, HH
+Valve HH has flow rate=22; tunnel leads to valve GG
+Valve II has flow rate=0; tunnels lead to valves AA, JJ
+Valve JJ has flow rate=21; tunnel leads to valve II
diff --git a/2022/16/test.js b/2022/16/test.js
new file mode 100644
index 0000000..44c122e
--- /dev/null
+++ b/2022/16/test.js
@@ -0,0 +1,34 @@
+import { test, expect, describe } from "vitest";
+
+import { expectSolution } from "../01/main.js";
+import part1, { sample, puzzleInput } from "./part1.js";
+import part2 from "./part2.js";
+
+describe("part 1", () => {
+    test( "input", ()=> {
+        expect(sample).toMatchObject({AA: {
+            exists: [
+                'DD', 'II', 'BB',
+            ],
+                flow: 0,
+        }})
+        
+    } )
+  test("sample", () => {
+    expect(part1(sample)).toEqual(1651);
+  });
+  test("solution", () => {
+        const r= part1(puzzleInput);
+        expect(r).toBeGreaterThan(707);
+    expectSolution(part1(puzzleInput)).toEqual(1871);
+  });
+});
+
+describe.only("part 2", () => {
+  test.skip("sample", () => {
+    expect(part2(sample)).toEqual(1707);
+  });
+  test("solution", () => {
+    expectSolution(part2(puzzleInput)).toEqual("TODO");
+  });
+});
diff --git a/package.json b/package.json
index 86b09f3..b49046c 100644
--- a/package.json
+++ b/package.json
@@ -12,13 +12,19 @@
   "license": "ISC",
   "dependencies": {
     "@a-robu/victor": "^2.2.2",
+    "@yanick/vyktor": "link:../vyktor",
+    "combinatorial-generators": "^1.1.2",
     "debug": "^4.3.4",
     "fs-extra": "^11.1.0",
+    "graphology": "^0.25.1",
+    "graphology-shortest-path": "^2.0.1",
+    "graphology-types": "^0.24.5",
     "memoizerific": "^1.11.3",
     "prettier": "^2.8.0",
     "remeda": "^1.3.0",
-    "vite": "^4.0.1",
-    "vitest": "0.25.7"
+    "updeep": "^1.2.1",
+    "vite": "4.0.3",
+    "vitest": "0.26.3"
   },
   "devDependencies": {
     "@vitest/ui": "^0.25.8"