Adent of Code 4.1

aoc-4-1.js

// const range = 136760-595730
const minimum = 136760
const maximum = 595730
let possiblePasswords = 0

class PasswordChecker {
  check(password) {
    password = password.split("")

    const hasJointDuplicates = this.hasJointDuplicates(password)

    if (!hasJointDuplicates) { return false }
    const followsIncrementRule = this.followsIncrementRule(password)

    if (!followsIncrementRule) { return false }
    return true
  }

  hasJointDuplicates(password) {
    const duplicate = password.find((character, index) => character == password[index + 1])
    return duplicate != undefined
  }

  followsIncrementRule(password) {
    for (var i = 0; i < password.length; i++) {
      const character = password[i]
      const nextCharacter = password[i+1]
      if (nextCharacter == undefined) {
        return true
      }
      if (character <= nextCharacter == false) {
        return false
      }
    }
    return true
  }
}

const checker = new PasswordChecker()

for (var i = minimum; i < maximum + 1; i++) {
  if (checker.check(i + "")) {
    possiblePasswords++
  }
}

console.log(possiblePasswords)