advent-of-code

commit 36f3726b488bf16bef7c5d7fc1cc94d2145b4d46
parent 958abb797bc364dd7ce30ad02cd6d3742bf79143
Author: finwo <finwo@pm.me>
Date:   Sun,  4 Dec 2022 19:44:24 +0100

2022/03 solution

Diffstat:
A
2022/day-03/index.js
 | 
93
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 93 insertions(+), 0 deletions(-)
diff --git a/2022/day-03/index.js b/2022/day-03/index.js
@@ -0,0 +1,93 @@
+const fs            = require('fs');
+const through       = require('through2');
+const line_for_line = require('../common/line-for-line');
+
+let priority      = 0;
+let priorityGroup = 0;
+
+let startA = 'a'.charCodeAt(0);
+let stopA  = 'z'.charCodeAt(0);
+let startB = 'A'.charCodeAt(0);
+let stopB  = 'Z'.charCodeAt(0);
+
+fs.createReadStream('input')
+  .pipe(line_for_line())
+
+  // Business logic
+  .pipe(through(function(line, enc, cb) {
+    line = line.toString();
+
+    const compartmentA = line.substr(0, line.length / 2);
+    const compartmentB = line.substr(line.length / 2);
+
+    for(let i=0; i<compartmentA.length; i++) {
+      const c = compartmentA.substr(i, 1);
+      const C = c.charCodeAt(0);
+      if (!~compartmentB.indexOf(c)) continue;
+
+      // console.log(`FOUND ${c} in ${compartmentA} and ${compartmentB}`);
+      if (startA <= C && C <= stopA) {
+        priority += 1 + C - startA;
+      } else if (startB <= C && C <= stopB) {
+        priority += 27 + C - startB;
+      }
+
+      break;
+    }
+
+    cb();
+  }))
+
+  .on('finish', () => {
+    // done
+    console.log('Priority', priority);
+  });
+
+let groupBuffer = [];
+fs.createReadStream('input')
+  .pipe(line_for_line())
+
+  // Group by 3
+  .pipe(through(function(line, enc, cb) {
+    line = line.toString();
+    groupBuffer.push(line);
+    if (groupBuffer.length == 3) {
+      this.push(JSON.stringify(groupBuffer));
+      groupBuffer = [];
+    }
+    cb();
+  }))
+
+  // Business logic
+  .pipe(through(function(line, enc, cb) {
+    const [x,y,z] = JSON.parse(line);
+    // Find the badge
+
+    // Iterate the one, as it must have the badge
+    for(let i=0; i<x.length; i++) {
+
+      // Filter down to the badge
+      const c = x.substr(i, 1);
+      const C = c.charCodeAt(0);
+      if (!~y.indexOf(c)) continue;
+      if (!~z.indexOf(c)) continue;
+
+      // console.log(`FOUND ${c} in group [${x}, ${y}, ${z}]`);
+      if (startA <= C && C <= stopA) {
+        priorityGroup += 1 + C - startA;
+      } else if (startB <= C && C <= stopB) {
+        priorityGroup += 27 + C - startB;
+      }
+
+      break;
+    }
+
+    // console.log(JSON.parse(line));
+    cb();
+  }))
+
+
+  .on('finish', () => {
+    // done
+    console.log('PriorityGroup', priorityGroup);
+  })