Advent of Code 2022 - Day 6: Tuning Trouble Solution

Part 1

To check a substring has all different characters:

• put all characters to a set
• if the size of the set is the same as the length of the substring, then no duplication characters are existed

Implementation

1const fs = require("fs")
2
3const readData = () => {
4  const data = fs.readFileSync("./input", "utf-8").split(/\r?\n/)
5
6  return data[0]
7}
8
9const main = () => {
10  const data = readData()
11  let res
12  const SIZE = 4
13
14  for (let i = 0; i < data.length - SIZE + 1; i++) {
15    const marker = data.substring(i, i + SIZE)
16    const isAllDifferent = new Set(marker.split("")).size === SIZE
17
18    if (isAllDifferent) {
19      res = i + SIZE
20      break
21    }
22  }
23
24  console.log(res)
25}
26
27main()

Part 2

Like Part 1, just change the SIZE to 14

Implementation

1const fs = require("fs")
2
3const readData = () => {
4  const data = fs.readFileSync("./input", "utf-8").split(/\r?\n/)
5
6  return data[0]
7}
8
9const main = () => {
10  const data = readData()
11  let res
12  const SIZE = 14
13
14  for (let i = 0; i < data.length - SIZE + 1; i++) {
15    const marker = data.substring(i, i + SIZE)
16    const isAllDifferent = new Set(marker.split("")).size === SIZE
17
18    if (isAllDifferent) {
19      res = i + SIZE
20      break
21    }
22  }
23
24  console.log(res)
25}
26
27main()

References

Original problem