advent-of-code

commit e7d27a87e980ff7cda7665f5465b74cec156b0b2
parent 91c9b62b74133b2f30c75bb3ee41198bfa15b785
Author: finwo <finwo@pm.me>
Date:   Thu, 22 Dec 2022 18:53:52 +0100

2022/21 solution

Diffstat:
A
2022/day-21/index.js
 | 
70
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
2022/day-21/sample
 | 
15
+++++++++++++++
M
2022/package-lock.json
 | 
14
++++++++++++++
M
2022/package.json
 | 
1
+

4 files changed, 100 insertions(+), 0 deletions(-)
diff --git a/2022/day-21/index.js b/2022/day-21/index.js
@@ -0,0 +1,70 @@
+const fs           = require('fs');
+const through      = require('through2');
+const line_by_line = require('../common/line-for-line');
+const nerdamer     = require('nerdamer/all.min');
+
+const step1 = {};
+const step2 = { equation: '', subst: {'humn':'x'} };
+
+// fs.createReadStream('sample')
+fs.createReadStream('input')
+  .pipe(line_by_line())
+
+  // Minor parsing
+  .pipe(through.obj(function(line, enc, cb) {
+    line = line.toString();
+
+    const [id, definition] = line.split(':').map(s => s.trim());
+
+    // Number = assign directly
+    if (!isNaN(definition)) {
+      step1[id] = () => parseInt(definition);
+      if (id !== 'humn') step2.subst[id] = definition;
+      return cb();
+    }
+
+    // Split & track substitution
+    step2.subst[id] = definition;
+    let [left, operation, right] = definition.split(' ');
+
+    if (id == 'root') {
+      step2.equation = `${left} = ${right}`;
+    }
+
+    step1[id] = () => {
+      if (!right) return step1[left]();
+      const l = step1[left]();
+      const r = step1[right]();
+      switch(operation) {
+        case '+': return l + r;
+        case '-': return l - r;
+        case '/': return l / r;
+        case '*': return l * r;
+      }
+    };
+
+    cb();
+  }))
+
+  .on('finish', () => {
+    console.log('loaded');
+
+    // First do step 1
+    const step1_result = step1.root();
+
+    // Expand step2 equation
+    let replaced;
+    do {
+      replaced = false;
+      for(const [token,op] of Object.entries(step2.subst)) {
+        if (~step2.equation.indexOf(token)) {
+          replaced = true;
+          step2.equation = step2.equation.replace(`${token}`, `(${op})`);
+        }
+      }
+    } while(replaced);
+
+    const solved = nerdamer.solveEquations(step2.equation, 'x');
+
+    console.log({ step1: step1_result, step2: solved.toString() });
+  });
diff --git a/2022/day-21/sample b/2022/day-21/sample
@@ -0,0 +1,15 @@
+root: pppw + sjmn
+dbpl: 5
+cczh: sllz + lgvd
+zczc: 2
+ptdq: humn - dvpt
+dvpt: 3
+lfqf: 4
+humn: 5
+ljgn: 2
+sjmn: drzm * dbpl
+sllz: 4
+pppw: cczh / lfqf
+lgvd: ljgn * ptdq
+drzm: hmdt - zczc
+hmdt: 32
diff --git a/2022/package-lock.json b/2022/package-lock.json
@@ -9,6 +9,7 @@
       "version": "1.0.0",
       "license": "MIT",
       "dependencies": {
+        "nerdamer": "^1.1.13",
         "through2": "^4.0.2"
       },
       "devDependencies": {
@@ -88,6 +89,14 @@
         "object-assign": "^4.1.0"
       }
     },
+    "node_modules/nerdamer": {
+      "version": "1.1.13",
+      "resolved": "https://registry.npmjs.org/nerdamer/-/nerdamer-1.1.13.tgz",
+      "integrity": "sha512-kQGQYd42eQpKDOnU8ZnRKF47c+gK6jVC46eUchrABsovtFruHvsjyjBO32jck8QnpZE5z5R8HQw72hQX9Oq2MQ==",
+      "engines": {
+        "node": ">=0.10.0"
+      }
+    },
     "node_modules/object-assign": {
       "version": "4.1.1",
       "resolved": "https://registry.npmjs.org/object-assign/-/object-assign-4.1.1.tgz",
@@ -232,6 +241,11 @@
         "object-assign": "^4.1.0"
       }
     },
+    "nerdamer": {
+      "version": "1.1.13",
+      "resolved": "https://registry.npmjs.org/nerdamer/-/nerdamer-1.1.13.tgz",
+      "integrity": "sha512-kQGQYd42eQpKDOnU8ZnRKF47c+gK6jVC46eUchrABsovtFruHvsjyjBO32jck8QnpZE5z5R8HQw72hQX9Oq2MQ=="
+    },
     "object-assign": {
       "version": "4.1.1",
       "resolved": "https://registry.npmjs.org/object-assign/-/object-assign-4.1.1.tgz",
diff --git a/2022/package.json b/2022/package.json
@@ -10,6 +10,7 @@
   "author": "",
   "license": "MIT",
   "dependencies": {
+    "nerdamer": "^1.1.13",
     "through2": "^4.0.2"
   },
   "devDependencies": {