solved bonus challenge

Author: chinesedfan

Diff for: README.md

@@ -81,3 +81,10 @@ For hardness: S(Simple), M(Middle), H(Hard).
 | 23  |   S/M    | cpu/optimization                |
 | 24  |   M/M    | bfs, permutation                |
 | 25  |   S/-    | cpu, find first                 |
+
+## Bonus
+
+Download `input.txt` [here](https://gist.githubusercontent.com/topaz/15518587415ccd0468767aed4192bfd3/raw/c5bfd6a7d40eabe1ae8b9a0fb36a939cb0c5ddf4/bonuschallenge.txt).
+
+- `YEAR=2016 node index.js 26 < input.txt > bonus.out.1`
+- `YEAR=2016 node index.js 8 2 < bonus.out.1`

Diff for: lib/2016/day26.js

@@ -1,13 +1,13 @@
 'use strict';
 const _ = require('lodash');
 const rInstr = /(\w+) ([a-d]|-?\d+)(?: ([a-d]|-?\d+))?/;
-const jnzCache = {};
+const output = [];
 
 module.exports = function(part, data) {
     const instrs = _.map(data.split('\n'), (line) => rInstr.exec(line));
     let ip = 0;
     let regs = {
-        a: part == 1 ? 7 : 12,
+        a: 0,
         b: 0,
         c: 0,
         d: 0
@@ -16,7 +16,6 @@ module.exports = function(part, data) {
     while (ip < instrs.length) {
         ip = exec(regs, instrs, ip);
     }
-    console.log(ip + ':', regs.a, regs.b, regs.c, regs.d);
 };
 
 function exec(regs, instrs, ip) {
@@ -34,30 +33,16 @@ function exec(regs, instrs, ip) {
         regs[matches[2]]--;
         break;
     case 'jnz':
-        // try to find multiply
-        if (/[a-d]/.test(matches[2])) {
-            if (jnzCache[ip]) {
-                const k = matches[2];
-                const step = jnzCache[ip][k] / (jnzCache[ip][k] - regs[k]);
-                _.each(regs, (val, key) => {
-                    regs[key] = jnzCache[ip][key] + (regs[key] - jnzCache[ip][key]) * step;
-                });
-                delete jnzCache[ip];
-            } else {
-                jnzCache[ip] = _.clone(regs);
-            }
-        }
-
         if (getVal(regs, matches[2])) return ip + getVal(regs, matches[3]);
         break;
-    case 'tgl':
-        const target = instrs[ip + getVal(regs, matches[2])];
-        if (!target) break;
-
-        if (typeof target[3] == 'undefined') {
-            target[1] = target[1] == 'inc' ? 'dec' : 'inc';
+    case 'out':
+        const val = getVal(regs, matches[2]);
+        const ch = String.fromCharCode(val);
+        if (ch == '\n') {
+            console.log(output.join(''));
+            output.length = 0;
         } else {
-            target[1] = target[1] == 'jnz' ? 'cpy' : 'jnz';
+            output.push(ch);
         }
         break;
     default: