aoc-19.js

// C ← op(A, B)

let beforeIp;
let ip = 0;
let ipReg;
const regs = [1, 0, 0, 0, 0, 0];
const instructions = {
  setIp: (value, regs) => { beforeIp = regs[value]; ipReg = value; regs[value] = ip; },

  seti: ([a,b,c], r) => r[c] = a,
  setr: ([a,b,c], r) => r[c] = r[a],

  addi: ([a,b,c], r) => r[c] = r[a] + b,
  addr: ([a,b,c], r) => r[c] = r[a] + r[b],

  muli: ([a,b,c], r) => r[c] = r[a] * b,
  mulr: ([a,b,c], r) => r[c] = r[a] * r[b],

  bani: ([a,b,c], r) => r[c] = r[a] & b,
  banr: ([a,b,c], r) => r[c] = r[a] & r[b],

  bori: ([a,b,c], r) => r[c] = r[a] | b,
  borr: ([a,b,c], r) => r[c] = r[a] | r[b],

  gtir: ([a,b,c], r) => r[c] = Number(a > r[b]),
  gtri: ([a,b,c], r) => r[c] = Number(r[a] > b),
  gtrr: ([a,b,c], r) => r[c] = Number(r[a] > r[b]),

  eqir: ([a,b,c], r) => r[c] = Number(a === r[b]),
  eqri: ([a,b,c], r) => r[c] = Number(r[a] === b),
  eqrr: ([a,b,c], r) => r[c] = Number(r[a] === r[b]),
}

const program = require('fs').readFileSync('aoc-input-19', 'utf-8').trim()
  .split('\n')
  .map(line => {
    if (line.startsWith('#ip')) {
      return {
        action: instructions.setIp,
        value: Number(line.split(' ')[1]),
        line,
      }
    } else {
      const [inst, ...args] = line.split(' ');
      return {
        action: instructions[inst],
        value: args.map(Number),
        line,
      };
    }
  });

//apparently this instruction is not part of the program
const ipSetter = program.shift();
ipSetter.action(ipSetter.value, regs);

// 10551343
// part 2 doesn't really complete, but observation shows what formula to use to compute the result

// for part 1, uncomment next line
//regs[0] = 0;
let gen = 0;
while(ip >= 0 && ip < program.length) {
  ++gen;
  const instr = program[ip];

  instr.action(instr.value, regs);

  if (ipReg) {
    ++regs[ipReg];
    ip = regs[ipReg];
  } else {
    ++ip;
  }
}

console.log(gen, regs);

aoc-input-19

#ip 3
addi 3 16 3
seti 1 8 5
seti 1 0 4
mulr 5 4 2
eqrr 2 1 2
addr 2 3 3
addi 3 1 3
addr 5 0 0
addi 4 1 4
gtrr 4 1 2
addr 3 2 3
seti 2 3 3
addi 5 1 5
gtrr 5 1 2
addr 2 3 3
seti 1 4 3
mulr 3 3 3
addi 1 2 1
mulr 1 1 1
mulr 3 1 1
muli 1 11 1
addi 2 4 2
mulr 2 3 2
addi 2 19 2
addr 1 2 1
addr 3 0 3
seti 0 7 3
setr 3 2 2
mulr 2 3 2
addr 3 2 2
mulr 3 2 2
muli 2 14 2
mulr 2 3 2
addr 1 2 1
seti 0 1 0
seti 0 5 3