2f:[{"id":"bd9f78ac7bf101c20238f28b89426313cac8ee1e1bd89c59bfa73616daabc36d9e4f8531594a3f9a262daa22a717aa83040100513c53d4923db45219bfcf01f5","href":"https://static.observableusercontent.com/files/bd9f78ac7bf101c20238f28b89426313cac8ee1e1bd89c59bfa73616daabc36d9e4f8531594a3f9a262daa22a717aa83040100513c53d4923db45219bfcf01f5","name":"input.txt","type":"text/plain","lastModified":1670252343645.182,"size":9946}] 2d:{"title":"Day 5 - Supply Stacks","cells":[{"id":0,"value":"# Day 5 - [Supply Stacks](https://adventofcode.com/2022/day/5)","pinned":false,"hidden":false,"mode":"md"},{"id":7,"value":"inputs0 = ` [D] \n[N] [C] \n[Z] [M] [P]\n 1 2 3 \n\nmove 1 from 2 to 1\nmove 3 from 1 to 3\nmove 2 from 2 to 1\nmove 1 from 1 to 2`","pinned":true,"hidden":false,"mode":"ojs"},{"id":5,"value":"inputs = FileAttachment(\"input.txt\").text()","pinned":true,"hidden":false,"mode":"ojs"},{"id":46,"value":"// parse 2nd block of inputs (i.e. after the empty line) into objects with \"count\", \"from\" and \"to\" properties\nmovements = inputs\n .split(\"\\n\\n\")[1]\n .split(\"\\n\")\n .map((line) =>\n Object.fromEntries(\n line.split(\" \").reduce((acc, curr, idx, arr) => {\n if (idx % 2 == 1) {\n acc.push([arr[idx - 1], arr[idx]]);\n }\n return acc;\n }, [])\n )\n )","pinned":true,"hidden":false,"mode":"ojs"},{"id":11,"value":"// split the 1st stacks block into lines (i.e. before the empty line)\nstacks = inputs.split(\"\\n\\n\")[0].split(\"\\n\")","pinned":true,"hidden":false,"mode":"ojs"},{"id":58,"value":"// stack IDs are taken from the last line of this block\nkeys = stacks[stacks.length - 1].split(\" \").filter((el) => el != \"\")","pinned":true,"hidden":false,"mode":"ojs"},{"id":61,"value":"// ... and their indexes in each string is derived by finding their ID in the last line\nindexes = keys.map((key) => stacks[stacks.length - 1].indexOf(key))","pinned":true,"hidden":false,"mode":"ojs"},{"id":74,"value":"// reformat as mapping from key to index\nindexFromKey = Object.fromEntries(keys.map((key, idx) => [key, indexes[idx]]))","pinned":true,"hidden":false,"mode":"ojs"},{"id":66,"value":"// finally parse the stacks into a list of lists\nstack = indexes.map((index) =>\n stacks\n .slice(0, -1)\n .reverse()\n .map((line) => line[index])\n .filter((el) => el != \" \")\n)","pinned":true,"hidden":false,"mode":"ojs"},{"id":164,"value":"// print ASCII map of elves with title\nprintStacks = (stack, move) => {\n let result = new Array(\n stack.reduce((max, line) => (line.length > max ? line.length : max), 0) + 1\n )\n .fill(\" \")\n .map((line) => new Array(4 * stack.length).fill(\" \"));\n\n stack.forEach((line, y) => {\n line.forEach((el, x, arr) => {\n result[result.length - x - 2][indexes[y] - 1] =\n (x == arr.length - 1 ? \"\" : \"\") + \"[\";\n result[result.length - x - 2][indexes[y]] = el;\n result[result.length - x - 2][indexes[y] + 1] =\n \"]\" + (x == arr.length - 1 ? \"\" : \"\");\n });\n result[result.length - 1][indexes[y]] = \"\" + y;\n });\n\n if (move > 0) {\n return html`\n

move #${move}

${result.map((line) => line.join(\"\")).join(\"\\n\")}

\n `;\n } else {\n return html`\n

${result.map((line) => line.join(\"\")).join(\"\\n\")}

\n `;\n }\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":196,"value":"printStacks(stack)","pinned":true,"hidden":false,"mode":"ojs"},{"id":146,"value":"## Part 1","pinned":false,"hidden":false,"mode":"md"},{"id":86,"value":"// apply the movements to the input stacks (moving items one-by-one, i.e. reversing their order)\nmovedStacks1 = {\n let movedStacks = Object.fromEntries(\n keys.map((key, idx) => [key, stack[idx].map((el) => el)])\n );\n\n let cnt = 0;\n for (let mv of movements) {\n cnt++;\n for (let n = 0; n < Number(mv.move); n++) {\n movedStacks[mv.to].push(movedStacks[mv.from].pop());\n yield {\n move: cnt,\n stacks: movedStacks\n };\n }\n }\n\n yield {\n move: cnt,\n stacks: movedStacks\n };\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":199,"value":"printStacks(Object.values(movedStacks1.stacks), movedStacks1.move)","pinned":true,"hidden":false,"mode":"ojs"},{"id":113,"value":"// string of uppermost characters of each stack\nresult1 = Object.values(movedStacks1.stacks)\n .map((stack) => stack[stack.length - 1])\n .join(\"\")","pinned":true,"hidden":false,"mode":"ojs"},{"id":148,"value":"## Part 2","pinned":false,"hidden":false,"mode":"md"},{"id":123,"value":"// apply movements to the input stacks, but with multiple items at once (i.e. preserving their order)\nmovedStacks2 = {\n let movedStacks = Object.fromEntries(\n keys.map((key, idx) => [key, stack[idx].map((el) => el)])\n );\n\n let cnt = 0;\n for (let mv of movements) {\n cnt++;\n let tmpStack = [];\n for (let n = 0; n < Number(mv.move); n++) {\n tmpStack.push(movedStacks[mv.from].pop());\n }\n\n for (let n = 0; n < Number(mv.move); n++) {\n movedStacks[mv.to].push(tmpStack.pop());\n }\n\n yield {\n move: cnt,\n stacks: movedStacks\n };\n }\n\n yield {\n move: cnt,\n stacks: movedStacks\n };\n}","pinned":true,"hidden":false,"mode":"ojs"},{"id":204,"value":"printStacks(Object.values(movedStacks2.stacks), movedStacks2.move)","pinned":true,"hidden":false,"mode":"ojs"},{"id":131,"value":"// string of uppermost characters of each stack\nresult2 = Object.values(movedStacks2.stacks)\n .map((stack) => stack[stack.length - 1])\n .join(\"\")","pinned":true,"hidden":false,"mode":"ojs"}],"files":"$W2f","stdlib":"1","titling":"auto"}