Advent of Code 2022 - Day 10: Cathode-Ray Tube Solution

Part 1

Straightforward implementation, just do as the instructions

Extract executeCycle function for better readability

Implementation

1const fs = require("fs")
2
3const readData = () => {
4  const data = fs
5    .readFileSync("./input", "utf-8")
6    .split(/\r?\n/)
7    .map(row => row.split(" "))
8
9  return data
10}
11
12const main = () => {
13  const data = readData()
14
15  let cycle = 1
16  let x = 1
17  let res = 0
18  let cycleToCheck = 20
19
20  const executeCycle = () => {
21    if (cycle === cycleToCheck) {
22      res += cycle * x
23      cycleToCheck += cycleToCheck === 220 ? -cycleToCheck : 40
24    }
25    cycle++
26  }
27
28  for (const [instruction, param] of data) {
29    switch (instruction) {
30      case "noop": {
31        executeCycle()
32        break
33      }
34      case "addx": {
35        executeCycle()
36        executeCycle()
37        x += +param
38        break
39      }
40    }
41  }
42
43  console.log(res)
44}
45
46main()

Part 2

Update initial cycleToCheck to 40

Be careful about index manipulation

1// eg.
2const crtRowPixel = cycle % 40 === 0 ? 40 : cycle % 40

Implementation

1const fs = require("fs")
2
3const readData = () => {
4  const data = fs
5    .readFileSync("./input", "utf-8")
6    .split(/\r?\n/)
7    .map(row => row.split(" "))
8
9  return data
10}
11
12const main = () => {
13  const data = readData()
14
15  let x = 1
16  let cycle = 1
17  let cycleToCheck = 40
18  let res = []
19  let crtRow = ""
20
21  const executeCycle = () => {
22    const crtRowPixel = cycle % 40 === 0 ? 40 : cycle % 40
23    const isLitPixelProducible = x <= crtRowPixel && crtRowPixel <= x + 2
24
25    crtRow += isLitPixelProducible ? "#" : "."
26
27    if (cycle === cycleToCheck) {
28      res.push(crtRow)
29      crtRow = ""
30      cycleToCheck += cycleToCheck === 240 ? -cycleToCheck : 40
31    }
32
33    cycle++
34  }
35
36  for (const [instruction, param] of data) {
37    switch (instruction) {
38      case "noop": {
39        executeCycle()
40        break
41      }
42      case "addx": {
43        executeCycle()
44        executeCycle()
45        x += +param
46        break
47      }
48    }
49  }
50
51  console.log(res.join("\n"))
52}
53
54main()

References

Original problem