2f:Ta0b,class Grid { constructor(pool, offset = 0) { this.pool = pool; this.offset = offset; } getNext() { return new Grid(this.pool, this.offset + 7 * 9); } get(x, y) { return this.pool[this.offset + 9 * x + y]; } set(x, y, v) { this.pool[this.offset + 9 * x + y] = v; } get hash() { return this.pool.subarray(this.offset, this.offset + 7 * 9).toBase64(); // return siphash(this.pool.subarray(this.offset, this.offset + 7 * 9)); /* let h = 0n; const end = this.offset + 63; for (let i = this.offset; i < end; ++i) { h <<= 3n; h += BigInt(this.pool[i]); } return h; */ } genComponents(c) { c.fill(0); let id = 10; let value; const self = this, colorsSeen = new Set(); for (let x = 0; x < 7; ++x) { for (let y = 0; y < 9; ++y) { value = this.get(x, y); if (!value || c[9 * x + y]) continue; colorsSeen.add(value); fill(x, y); id++; } } return [id - 1, colorsSeen.size]; function fill(x, y, dir) { if (c[9 * x + y] || self.get(x, y) !== value) return; c[9 * x + y] = id; if (dir != 2 && x > 0) fill(x - 1, y, 1); if (dir != 1 && x < 6) fill(x + 1, y, 2); if (dir != 4 && y > 0) fill(x, y - 1, 3); if (dir != 3 && y < 8) fill(x, y + 1, 4); } } tap1(prev, comp, id) { for (let x = 0; x < 63; x += 9) { let y2 = 0; for (let y = 0; y < 9; ++y) { if (comp[x + y] == id) continue; this.pool.copyWithin( this.offset + x + y2++, prev.offset + x + y, prev.offset + x + y + 1 ); } } return this; } tap(prev, comp, id) { this.pool.copyWithin(this.offset, prev.offset, prev.offset + 63); let i = 63; while (i > 0) { // Find last appearance i = comp.lastIndexOf(id, --i); if (i === -1) break; // Search backwards to start of row let j = i - 1; while (j % 9 >= 0 && comp[j] === id) --j; const rowPos = i % 9, count = i - j, nextRowStart = this.offset + i - rowPos + 9; // Shift over end of row if needed if (rowPos < 8) { this.pool.copyWithin( this.offset + j + 1, this.offset + i + 1, nextRowStart ); } // Zero end const nextZero = this.pool.indexOf(0, this.offset + i); const zeroStart = Math.min(nextZero, nextRowStart - count); this.pool.fill(0, zeroStart, nextRowStart); i = j; } // return this; } }30:T46c,function step3(state, seen, c, skip, best = 100) { const fac = new GridFactory(state.fac), step = state.step + 1; let newgrid = fac.make(); const grids = []; const colorsSeen = []; for (let i = state.progress; i < state.grids.length; i += skip) { const prev = state.grids[i], grid = prev.grid, [maxId, colors] = grid.genComponents(c); if (maxId === 10) return { solution: { tapped: 10, prev }, step }; // Check if there's any hope of beating best if (state.step + colors < best) { // Tap in random order const ids = shuffle(_.range(10, maxId + 1)); for (const id of ids) { newgrid.tap(grid, c, id); // causes OOM: if (checkSeen(newgrid.hash, step)) continue; grids.push({ grid: newgrid, tapped: id, prev }); newgrid = fac.make(); } } } shuffle(grids); return { fac, grids, step, progress: 0 }; function checkSeen(hash, step) { const match = seen.get(hash); if (match && match <= step) { seen.stats.t++; return true; } seen.set(hash, step); seen.stats.f++; return false; } }31:T585,solver = { const ladder = [{ fac: g1.fac, grids: g1.grids, step: 0, progress: 0 }], c = new Uint8Array(7 * 9), seen = new Map(); seen.stats = { t: 0, f: 0 }; const value = { ladder, stats: seen.stats, best: 100 }; for (let n = 0; n < 5; ++n) { ladder.push(step3(ladder[n], seen, c, 1)); ladder[n].progress = skipsize; yield value; } purgeSeen(); try { let t = Date.now(); while (enabled) { const lastStep = ladder.at(-1), newStep = step3(lastStep, seen, c, skipsize, value.best); if (newStep.solution) { value.best = newStep.step; value.solution = newStep.solution; lastStep.progress = skipsize; purgeSeen(); } else if (newStep.grids.length !== 0) { ladder.push(newStep); } else { lastStep.progress++; } while (ladder.at(-1).progress === skipsize) { ladder.pop(); ladder.at(-1).progress++; } value.allProg = ladder.map((it) => it.progress).toString(); if (Date.now() - t >= 100) { yield value; t = Date.now(); } } value.done = true; } catch (err) { value.error = err; } value.ladder = ladder; yield value; function purgeSeen() { seen.forEach((v, k, m) => { if (v >= value.best) m.delete(k); }); const s = seen.stats; s.size = seen.size; s.ratio = s.f / (s.t + s.f); } }32:[{"id":"ca89dea4ef294c865cccf35e1fe13c6d60c86ae2215270eb22e1fef83802696a2b6f546965a949a3d7a257bb7b515186f13722d2a3cf9eb4ecba48f9630a7705","href":"https://static.observableusercontent.com/files/ca89dea4ef294c865cccf35e1fe13c6d60c86ae2215270eb22e1fef83802696a2b6f546965a949a3d7a257bb7b515186f13722d2a3cf9eb4ecba48f9630a7705","name":"Screenshot_20250718-212736.png","type":"image/png","lastModified":1752866925079.262,"size":200767}] 2d:{"title":"Solver","cells":[{"id":0,"value":"# Solver","pinned":false,"hidden":false,"mode":"md"},{"id":3,"value":"img = FileAttachment(\"Screenshot_20250718-212736.png\").image()","pinned":true,"hidden":false,"mode":"ojs"},{"id":17,"value":"[img.naturalWidth, img.naturalHeight]","pinned":true,"hidden":false,"mode":"ojs"},{"id":79,"value":"pad=26","pinned":true,"hidden":false,"mode":"ojs"},{"id":21,"value":"c = {\n const c = htl.html`