Reimplemeted day 7 as a code exercise

2022/7/take-2.js

@@ -0,0 +1,48 @@
+// I wanted to try this one again with a different approach just as an exercise
+// in a more complex, but faster way implementing the solutions
+
+const fs = require('fs/promises');
+
+(async () => {
+  const input = (await fs.readFile("./input.txt", 'utf8')).split("\n");;
+
+  const path = [];
+
+  const dirsMap = {};
+
+  for (const line of input) {
+    console.log("PATH ", path);
+    if(line === "$ cd /") {
+      continue;
+    }
+    if(line === "$ cd ..") {
+      path.pop();
+      continue;
+    }
+    const cdCmd = line.match(/\$ cd (.+)/);
+    if(cdCmd) {
+      const [_, cdDir] = cdCmd;
+      path.push(cdDir);
+      continue;
+    }
+    const file = line.match(/^\d+/);
+    if(file) {
+      const [size] = file;
+      updateDirsOnPath(dirsMap, ["root", ...path], parseFloat(size));
+      continue;
+    }
+  }
+
+  console.log("ANSWER: ", sum(Object.values(dirsMap).filter(x => x <= 100000)))
+
+  console.log("ANSWER 2: ", Object.values(dirsMap).reduce((best, cur) => cur > dirsMap.root - 40000000 && cur < best ? cur : best, Infinity));
+})();
+
+const updateDirsOnPath = (dirsMap, path, size) => {
+  if(!path.length) return;
+  const pwd = path.join("/");
+  dirsMap[path] = (dirsMap[path] || 0) + size;
+  updateDirsOnPath(dirsMap, path.slice(0, -1), size);
+}
+
+const sum = (arr) => arr.reduce((total, num) => total+num, 0);