advent-of-code

commit 20c9963950516dc1108d5b81c37c2542ec490bc5
parent 3cab6425a0cbaf1b422e87a030660f94d27440ec
Author: finwo <finwo@pm.me>
Date:   Tue, 15 Nov 2022 15:22:38 +0100

Added 2015/02 answer

Diffstat:
A
2015/day-02/index.js
 | 
78
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 78 insertions(+), 0 deletions(-)
diff --git a/2015/day-02/index.js b/2015/day-02/index.js
@@ -0,0 +1,78 @@
+const fs = require('fs');
+const through = require('through2');
+
+let total = 0;
+let ribbon = 0;
+
+fs.createReadStream('input')
+
+  // Convert to characters
+  .pipe(through(function(chunk, enc, cb) {
+    chunk = chunk.toString();
+    for(let i = 0; i < chunk.length; i++) {
+      this.push(chunk.charAt(i));
+    }
+    cb();
+  }))
+
+  // Normalize newlines
+  .pipe(through(function(chunk, enc, cb) {
+    chunk = chunk.toString();
+    switch(chunk) {
+      case '\r':
+        if (this.osx) {
+          this.push('\n');
+        }
+        this.osx = true;
+        break;
+      default:
+        if (this.osx) {
+          if (chunk !== '\n') {
+            this.push('\n');
+          }
+          this.osx = false;
+        }
+        this.push(chunk);
+        break;
+    }
+    cb();
+  }))
+
+  // Convert characters to lines
+  .pipe(through(function(chunk, enc, cb) {
+    if (!this.buf) this.buf = Buffer.alloc(0);
+    if (chunk.toString() == '\n') {
+      this.push(this.buf);
+      this.buf = Buffer.alloc(0);
+      return cb();
+    }
+    const buf = Buffer.alloc(this.buf.length + chunk.length);
+    this.buf.copy(buf, 0);
+    chunk.copy(buf, this.buf.length);
+    this.buf = buf;
+    cb();
+  }))
+
+  // Business logic
+  // Convert to dimensions
+  .pipe(through.obj(function(chunk, enc, cb) {
+    this.push(chunk.toString().split('x').map(c => parseInt(c)));
+    cb();
+  }))
+
+  // Business logic
+  // Convert to wrapping paper required for the package
+  .pipe(through.obj(function(dimensions, enc, cb) {
+    const w = dimensions[0], h = dimensions[1], l = dimensions[2];
+    const planes = [w*h,h*l,l*w];
+    const ribbons = [2*(w+h), 2*(h+l), 2*(l+w)];
+    total += planes.reduce((r, a) => r + (2*a), 0);
+    total += Math.min(...planes);
+    ribbon += Math.min(...ribbons) + (w*h*l);
+    cb();
+  }))
+
+  .on('finish', () => {
+    console.log(`The elfs need ${total} sqft of wrapping paper`);
+    console.log(`The elfs need ${ribbon} feet of ribbon`);
+  })