Discussion on: Advent of Code 2020 Solution Megathread - Day 5: Binary Boarding

package main

import (
    "bufio"
    "fmt"
    "os"
    "sort"
    "strings"
)

func getNumber(id string) int {
    num := 0
    l := len(id)
    for i := l - 1; i >= 0; i-- {
        if id[i] == 'B' || id[i] == 'R' {
            num |= 1 << (l - i - 1)
        }
    }
    return num
}

func getId(row, col int) int {
    return (row << 3) + col
}

func main() {
    reader := bufio.NewReader(os.Stdin)

    ids := make([]int, 0)
    for {
        var line string
        line, err := reader.ReadString('\n')
        if err != nil {
            break
        }

        line = strings.TrimSpace(line)
        ids = append(ids, getId(getNumber(line[:7]), getNumber(line[7:])))
    }

    sort.Ints(ids)
    fmt.Println(ids[len(ids) - 1])

    for i := 0; i < len(ids)-1; i++ {
        if ids[i+1]-ids[i] == 2 {
            fmt.Println(ids[i] + 1)
            break
        }
    }
}