feature: JSAbacusFramework.io

Author: mariotacke

Diff for: README.md

@@ -17,6 +17,7 @@ Collect stars by helping Santa solve puzzles. Two puzzles will be made available
 - [Day 9: All in a Single Night](day-09-all-in-a-single-night/)
 - [Day 10: Elves Look, Elves Say](day-10-elves-look-elves-say/)
 - [Day 11: Corporate Policy](day-11-corporate-policy/)
+- [Day 12: JSAbacusFramework.io](day-12-js-abacus-framework-io/)
 
 ## Running Tests
 

Diff for: day-12-js-abacus-framework-io/README.md

@@ -0,0 +1,19 @@
+# Day 12: JSAbacusFramework.io
+
+Santa's Accounting-Elves need help balancing the books after a recent order. Unfortunately, their accounting software uses a peculiar storage format. That's where you come in.
+
+They have a [JSON](http://json.org/) document which contains a variety of things: arrays (`[1,2,3]`), objects (`{"a":1, "b":2}`), numbers, and strings. Your first job is to simply find all of the **numbers** throughout the document and add them together.
+
+For example:
+
+- `[1,2,3]` and `{"a":2,"b":4}` both have a sum of `6`.
+- `[[[3]]]` and `{"a":{"b":4},"c":-1}` both have a sum of `3`.
+- `{"a":[-1,1]}` and `[-1,{"a":1}]` both have a sum of `0`.
+- `[]` and `{}` both have a sum of `0`.
+
+You will not encounter any strings containing numbers.
+
+What is the **sum of all numbers** in the document?
+
+## References
+- https://adventofcode.com/2015/day/12

Diff for: day-12-js-abacus-framework-io/abacus.js

@@ -0,0 +1,26 @@
+const traverse = (node) => {
+  if (Number.isInteger(node)) {
+    return node;
+  } else if (typeof node === 'string') {
+    return 0;
+  } else if (Array.isArray(node)) {
+    const sum = node
+      .map((x) => traverse(x))
+      .reduce((a, b) => a + b, 0);
+
+    return sum;
+  } else if (typeof node === 'object') {
+    return Object
+      .keys(node)
+      .map((k) => {
+        return traverse(node[k]);
+      })
+      .reduce((a, b) => a + b, 0);
+  }
+};
+
+const abacus = (input) => {
+  return traverse(input);
+};
+
+module.exports = abacus;

Diff for: day-12-js-abacus-framework-io/test.js

@@ -0,0 +1,16 @@
+const assert = require('assert');
+
+const abacus = require('./abacus');
+
+describe('Day 12: JSAbacusFramework.io', () => {
+  it('should calculate total number', () => {
+    assert.strictEqual(abacus([1, 2, 3]), 6);
+    assert.strictEqual(abacus({ 'a': 2, 'b': 4 }), 6);
+    assert.strictEqual(abacus([[[3]]]), 3);
+    assert.strictEqual(abacus({ 'a': { 'b': 4 }, 'c': -1 }), 3);
+    assert.strictEqual(abacus({ 'a': [-1, 1] }), 0);
+    assert.strictEqual(abacus([-1, { 'a': 1 }]), 0);
+    assert.strictEqual(abacus([]), 0);
+    assert.strictEqual(abacus({}), 0);
+  });
+});