75 lines
1.9 KiB
JavaScript
75 lines
1.9 KiB
JavaScript
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const fs = require('fs/promises');
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const createNode = (parent) => {
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return {
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parent,
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children: {},
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localSize: 0
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};
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};
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let answer = 0;
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(async () => {
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const input = await fs.readFile("./input.txt", 'utf8');
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const lines = input.split("\n");
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const files = createNode();
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lines.reduce((node, line) => {
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const cd = line.match(/^\$ cd (.*)$/);
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if(cd) {
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if(cd[1] == "..") {
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return node.parent;
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}
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return node.children[cd[1]];
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}
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const dir = line.match(/^dir (.*)$/);
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if(dir) {
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node.children[dir[1]] = createNode(node);
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}
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const file = line.match(/^(\d+) .*$/);
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if(file) {
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node.localSize += parseFloat(file[1]);
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}
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return node;
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}, files);
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const fullSize = totalSmallerDirs(files);
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console.log("FULL SIZE: ", fullSize);
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console.log("SPACE NEEDED: ", fullSize - 40000000);
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const [_, bestDeletionCandidate] = findBestDeletionCandidate(files, fullSize - 40000000);
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console.log("Best candidate for deletion is of size: ", bestDeletionCandidate);
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})();
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const totalSmallerDirs = (node) => {
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let totalSize = node.localSize;
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totalSize += sum(Object.values(node.children).map(totalSmallerDirs));
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if(totalSize <= 100000) {
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answer += totalSize;
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}
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return totalSize;
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}
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const findBestDeletionCandidate = (node, spaceNeeded) => {
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let totalSize = node.localSize;
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const childrenResults = Object.values(node.children).map(child => findBestDeletionCandidate(child, spaceNeeded));
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totalSize += sum(childrenResults.map(([x]) => x));
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const deletionCandidates = childrenResults.map(([_, y]) => y);
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deletionCandidates.push(totalSize);
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console.log("Deletion Candidates: ", deletionCandidates);
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return [totalSize, deletionCandidates.reduce((best, current) => current < best && current >= spaceNeeded ? current : best, Infinity)];
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}
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const sum = (arr) => arr.reduce((total, num) => total+num, 0);
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