day 7

2022/7.js

@@ -0,0 +1,63 @@
+const exp = require('constants');
+const fs = require('fs');
+
+const terminalLines = fs.readFileSync('7.input').toString().split('\n');
+
+const directoryTree = {
+    '': { size: 0, items: [] },
+};
+
+let exploratoryPath = [];
+for (let i in terminalLines) {
+    const line = terminalLines[i].split(' ');
+
+    if (terminalLines[i].startsWith('$')) {
+        if (line[1] == 'ls') continue;
+        switch (line[2]) {
+            case '/': exploratoryPath = []; break;
+            case '..': exploratoryPath.pop(); break;
+            default: exploratoryPath.push(line[2]); break;
+        }
+        if (!directoryTree[exploratoryPath]) {
+            directoryTree[exploratoryPath] = {};
+            directoryTree[exploratoryPath].items = [];
+            directoryTree[exploratoryPath].size = 0;
+        }
+
+    } else {
+        if (isNaN(parseInt(line[0]))) continue;
+        // we can assume it is a member of the active dir, exploratoryPath
+        const item = {
+            size: parseInt(line[0]),
+            name: line[1],
+        }
+        directoryTree[exploratoryPath].items.push(item);
+        directoryTree[exploratoryPath].size += item.size;
+        // recursively update parents to reflect new size
+        const tempPath = structuredClone(exploratoryPath);
+        while (tempPath.pop())
+            directoryTree[tempPath].size += item.size;
+    }
+}
+
+let part1 = 0;
+for (const dir in directoryTree) {
+    if (directoryTree[dir].size <= 100000) {
+        part1 += directoryTree[dir].size;
+    }
+}
+
+console.log(`Part 1: ${part1}`);
+
+let part2 = [];
+const fsUsedSpace = directoryTree[''].size;
+const fsMaxSpace = 70000000;
+const fsNeededSpace = 30000000;
+const fsDeleteMinSize = fsNeededSpace - (fsMaxSpace - fsUsedSpace)
+for (const dir in directoryTree) {
+    if (directoryTree[dir].size >= fsDeleteMinSize) {
+        part2.push(directoryTree[dir].size);
+    }
+}
+
+console.log(`Part 2: ${part2.sort((a, b) => a - b)[0]}`);