DAY 5 - Advent of Code 2020 w/ GoLang

package days

import (
    "fmt"
    "sort"

    inputs "../inputs"
)

// Five : advent of code, day five part1 and 2
func Five() {
    inputSlice := inputs.Day5

    seatIds := partOne(inputSlice)
    fmt.Println("")
    fmt.Println("Your seat ID is: ")
    fmt.Println(partTwo(seatIds))
}

func partOne(inputSlice []string) []int {
    seatIds := []int{}

    for dir := range inputSlice {
        toRune := []rune(inputSlice[dir])
        rowRange := []int{0, 128}
        colRange := []int{0, 8}
        finalRow := 0
        finalColumn := 0
        for i := 0; i < 7; i++ {
            if toRune[i] == 'F' {
                rowRange[1] = rowRange[1] - ((rowRange[1] - rowRange[0]) / 2)
            } else if toRune[i] == 'B' {
                rowRange[0] = rowRange[0] + ((rowRange[1] - rowRange[0]) / 2)
            }

            if i == 6 {
                finalRow = rowRange[0]
            }
        }

        for i := 0; i < 3; i++ {
            if toRune[i+7] == 'L' {
                colRange[1] = colRange[1] - ((colRange[1] - colRange[0]) / 2)
            } else if toRune[i+7] == 'R' {
                colRange[0] = colRange[0] + ((colRange[1] - colRange[0]) / 2)
            }

            if i == 2 {
                finalColumn = colRange[0]
            }
        }

        seatIds = append(seatIds, ((finalRow * 8) + finalColumn))
    }

    highest := 0
    for i := range seatIds {
        if seatIds[i] > highest {
            highest = seatIds[i]
        }
    }

    fmt.Print("Highest Seat ID: ")
    fmt.Println(highest)
    return seatIds
}

func partTwo(seatIds []int) int {
    sort.Ints(seatIds)
    seatsLeft := []int{}

    for i, seat := 0, seatIds[0]; seat < seatIds[len(seatIds)-1]; i, seat = i+1, seat+1 {
        if seat != seatIds[i] {
            seatsLeft = append(seatsLeft, seat)
            seat = seatIds[i]
        }
    }

    return seatsLeft[0]
}