advent-of-code

commit c17cc3ebd4a2040f9643bc15433edfcf37dece61
parent b7f551c0c23d3769430e1f36de8b8afd60872197
Author: finwo <finwo@pm.me>
Date:   Wed,  7 Dec 2022 11:26:06 +0100

2022/07 solution

Diffstat:
A
2022/day-07/index.js
 | 
108
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 108 insertions(+), 0 deletions(-)
diff --git a/2022/day-07/index.js b/2022/day-07/index.js
@@ -0,0 +1,108 @@
+const fs            = require('fs');
+const through       = require('through2');
+const line_for_line = require('../common/line-for-line');
+
+let pwd    = [];
+let vfs    = {};
+const size = Symbol('size');
+const dirs = {'/': 0};
+
+let totalsize = 70000000;
+
+function set(sub, path, value) {
+  // console.log('set', { sub, path, value });
+  path = path.slice();
+  const last = path.pop();
+  while(path.length) {
+    const token = path.shift();
+    sub = sub[token] = sub[token] || {};
+  }
+  sub[last] = value;
+}
+function get(sub, path) {
+  path = path.slice();
+  while(path.length) sub = sub[path.shift()];
+  return sub;
+}
+const sum = (r, a) => r + a;
+
+fs.createReadStream('input')
+  .pipe(line_for_line())
+
+  // Build directory structure
+  .pipe(through(function(line, enc, cb) {
+    line = line.toString();
+    process.stdout.write(`${pwd.join('/')}> ${line}\n`);
+    const [type, ...args] = line.split(' ');
+
+    if (!isNaN(type)) {
+      // File marker
+      const p = [...pwd, args[0]].join('/');
+      vfs[p] = parseInt(type);
+    } else if (type == 'dir') {
+      // Dir marker
+      const p = [...pwd, args[0]].join('/');
+      dirs[p] = 0;
+    } else if (type == '$') {
+      // Command marker
+      const cmd = args.shift();
+      switch(cmd) {
+        case 'cd':
+          if (args[0] === '..') pwd.pop();
+          else if (args[0] == '/') pwd = [];
+          else pwd.push(args[0]);
+          break;
+        default:
+          break;
+      }
+    } else {
+      throw new Error(`Unknown type: ${type}`);
+    }
+
+    // console.log(JSON.stringify({ type, args, vfs }, null, 2));
+    cb();
+  }))
+
+  // Actual tasks
+  .on('finish', () => {
+    // done
+
+    // Calculate size independently for each directory
+    for(let dir in dirs) {
+      if (!dirs.hasOwnProperty(dir)) continue;
+      if (dir == '/') {
+        dirs[dir] = Object.values(vfs).reduce((r,a)=>r+a, 0);
+        continue;
+      }
+      dir = dir + '/'
+      dirs[dir] = Object.entries(vfs)
+        .filter(([name, size]) => name.substr(0, dir.length) == dir)
+        .map(([name, size]) => size)
+        .reduce((r,a)=>r+a,0);
+    }
+
+    // Sum + threshold
+    const threshold   = 100000;
+    let   sum         = 0;
+    for(const size of Object.values(dirs)) {
+      if (size > threshold) continue;
+      sum += size;
+    }
+    console.log({ sum });
+
+    // Find smallest above threshold
+    let unusedSize = totalsize - dirs['/'];
+    let neededSize = 30000000;
+    let deleteSize = neededSize - unusedSize;
+    let selected   = '/';
+    for(const [name, size] of Object.entries(dirs)) {
+      if (size < deleteSize) continue;
+      if (size >= dirs[selected]) continue;
+      selected = name;
+    }
+
+    console.log({unusedSize, selected, 'sz': dirs[selected]});
+
+    // START -- En
+
+  });