advent-of-code

commit b7f551c0c23d3769430e1f36de8b8afd60872197
parent c839f6de1619258ebeffd960290afd4cbf10de4c
Author: finwo <finwo@pm.me>
Date:   Tue,  6 Dec 2022 07:15:27 +0100

2022/06 solution

Diffstat:
A
2022/day-06/index.js
 | 
45
+++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 45 insertions(+), 0 deletions(-)
diff --git a/2022/day-06/index.js b/2022/day-06/index.js
@@ -0,0 +1,45 @@
+const fs            = require('fs');
+const through       = require('through2');
+const char_for_char = require('../common/char-for-char.js');
+
+const histbuf = [];
+let   idx     = 0;
+let   L       = 14;
+
+function uniq(arr) {
+  return arr.filter((v, i, a) => a.indexOf(v) == i);
+}
+
+fs.createReadStream('input')
+  .pipe(char_for_char())
+
+  // Business logic
+  .pipe(through(function(char, enc, cb) {
+    char = char.toString();
+
+    // Append character
+    histbuf.push(char);
+    idx++;
+
+    // Bail if not enough characters
+    if (histbuf.length < L) {
+      return cb();
+    }
+
+    // Limit length
+    if (histbuf.length > L) {
+      histbuf.shift();
+    }
+
+    // Check for all unique characters
+    if (uniq(histbuf).length == L) {
+      console.log('START', idx);
+    }
+
+    // console.log({ histbuf, uniq: uniq(histbuf) });
+    cb();
+  }))
+
+  .on('finish', () => {
+    // done
+  });