31:T776,{ let dir = 'r'; let xy = 17; let matrix = Array.from({ length: xy }, () => Array.from({ length: xy }, () => null) ); let x = Math.floor(xy / 2); let y = Math.floor(xy / 2); for (let i = 1; i <= size; i++) { // console.log(dir, x, y, i); matrix[y][x] = i; switch (dir) { case 'r': if (matrix[y - 1][x] == null && i != 1) dir = 'u'; break; case 'u': if (matrix[y][x - 1] == null) dir = 'l'; break; case 'l': if (matrix[y + 1][x] == null) dir = 'd'; break; case 'd': if (matrix[y][x + 1] == null) dir = 'r'; break; } switch (dir) { case 'r': x += 1; break; case 'u': y -= 1; break; case 'l': x -= 1; break; case 'd': y += 1; break; } } let cellWidth = 3; //size.toString().length; if (layout == 'table') { return html`${matrix .map(d => { return d .map(i => { let v = i == null ? ''.padStart(cellWidth) : i.toString().padStart(cellWidth, 0); return ``; }) .join(' '); }) .join('')}

${v}

`; } else { return html`

${matrix
      .map(d => {
        return d
          .map(i => {
            let v =
              i == null
                ? ''.padStart(cellWidth)
                : i.toString().padStart(cellWidth, 0);
            if (i != null && primes.includes(i) && highlightPrimes == "true") {
              v = `${v}`;
            }
            return v;
          })
          .join(' ');
      })
      .join('\n')}

`; } }32:[] 2f:{"title":"Ulam Spiral","cells":[{"id":0,"value":"md`# [Ulam Spiral](https://en.wikipedia.org/wiki/Ulam_spiral)`","pinned":false,"hidden":false,"mode":"ojs"},{"id":460,"value":"viewof size = Scrubber(Array.from({ length: 306 }, (_, i) => i + 1), {\n loop: false\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":651,"value":"viewof layout = radio({\n title: 'Layout',\n options: [\n { label: 'Text', value: 'text' },\n { label: 'Table', value: 'table' }\n ],\n value: 'text'\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":594,"value":"viewof highlightPrimes = checkbox({\n options: [{ value: \"true\", label: \"Highlight Primes\" }],\n value: \"true\"\n})","pinned":false,"hidden":false,"mode":"ojs"},{"id":323,"value":"$31","pinned":false,"hidden":false,"mode":"ojs"},{"id":524,"value":"primes = {\n let size = 350;\n\n let p = Array.from({ length: size }, (_, i) => {\n return i + 1;\n });\n\n p[0] = null;\n\n for (let c = 0; c < size; c++) {\n if (p[c] == null) continue;\n for (let i = p[c] * 2 - 1; i < size; i += p[c]) {\n p[i] = null;\n }\n }\n\n return p.filter(Number);\n}","pinned":false,"hidden":false,"mode":"ojs"},{"id":642,"value":"html`\n`","pinned":true,"hidden":false,"mode":"ojs"},{"id":461,"value":"import { Scrubber } from \"@mbostock/scrubber\"","pinned":false,"hidden":false,"mode":"ojs"},{"id":270,"value":"import { slider, checkbox, radio } from \"@jashkenas/inputs\"","pinned":false,"hidden":false,"mode":"ojs"}],"files":"$W32","stdlib":"1","titling":"auto"}