71 lines
1.2 KiB
Go
71 lines
1.2 KiB
Go
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package main
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import (
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"fmt"
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h "git.bullercodeworks.com/brian/adventofcode/helpers"
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)
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func main() {
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inp := h.StdinToStringSlice()
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seats := make(map[int]Seat)
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var topSeat int
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for k := range inp {
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row, col, seat := findSeatFromId(inp[k])
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seats[seat] = Seat{
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Row: row,
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Col: col,
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Seat: seat,
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}
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if seat > topSeat {
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topSeat = seat
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}
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}
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fmt.Println("# Part 1 - Top Seat:", topSeat)
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for k := range seats {
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_, tOk := seats[k-1]
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if !tOk {
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_, bOk := seats[k-2]
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if bOk {
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fmt.Println("# Part 2 - Missing Seat:", k-1)
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break
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}
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}
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}
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}
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type Seat struct {
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Row int
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Col int
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Seat int
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}
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func findSeatFromId(id string) (int, int, int) {
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rowBeg := 0
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rowEnd := 127
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colBeg := 0
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colEnd := 7
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for k := range id {
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switch id[k] {
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case 'F', 'B':
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rowBeg, rowEnd = findChunk(rowBeg, rowEnd, id[k] == 'F')
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case 'R', 'L':
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colBeg, colEnd = findChunk(colBeg, colEnd, id[k] == 'L')
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}
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}
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return rowBeg, colBeg, (rowBeg * 8) + colBeg
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}
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func findChunk(beg, end int, front bool) (int, int) {
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if beg == end {
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return beg, beg
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}
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if front {
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return beg, beg + (end-beg)/2
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} else {
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return beg + (end-beg)/2 + 1, end
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}
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}
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