146 lines
2.9 KiB
Go
146 lines
2.9 KiB
Go
package day23
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import (
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"fmt"
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"os"
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"strings"
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)
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type Coord struct {
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Row, Col int
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}
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type CellType rune
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const (
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Path CellType = '.'
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Tree CellType = '#'
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SlideDown CellType = 'v'
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SlideUp CellType = '^'
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SlideLeft CellType = '<'
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SlideRight CellType = '>'
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)
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type Field struct {
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MaxRow, MaxCol int
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Cells map[Coord]CellType
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StartCol, EndCol int
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}
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func (f *Field) EndCoord() Coord {
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return Coord{Row: f.MaxRow, Col: f.EndCol}
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}
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func (f *Field) NeighborsPart2(c Coord) (neighbors []Coord) {
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symb, exists := f.Cells[c]
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if !exists {
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panic(fmt.Sprintf("coord %+v not found in field", c))
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}
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var coords []Coord
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switch symb {
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case Tree:
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panic(fmt.Sprintf("attempting to get neighbors of a tree at %+v", c))
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default:
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coords = []Coord{
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{Row: c.Row + 1, Col: c.Col},
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{Row: c.Row - 1, Col: c.Col},
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{Row: c.Row, Col: c.Col + 1},
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{Row: c.Row, Col: c.Col - 1},
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}
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}
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for _, coord := range coords {
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neighborSymb, found := f.Cells[coord]
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if !found || neighborSymb == Tree {
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continue
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}
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neighbors = append(neighbors, coord)
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}
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return
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}
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func (f *Field) Neighbors(c Coord) (neighbors []Coord) {
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symb, exists := f.Cells[c]
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if !exists {
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panic(fmt.Sprintf("coord %+v not found in field", c))
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}
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var coords []Coord
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switch symb {
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case Path:
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coords = []Coord{
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{Row: c.Row + 1, Col: c.Col},
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{Row: c.Row - 1, Col: c.Col},
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{Row: c.Row, Col: c.Col + 1},
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{Row: c.Row, Col: c.Col - 1},
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}
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case Tree:
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panic(fmt.Sprintf("attempting to get neighbors of a tree at %+v", c))
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case SlideDown:
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coords = []Coord{{Row: c.Row + 1, Col: c.Col}}
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case SlideUp:
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coords = []Coord{{Row: c.Row - 1, Col: c.Col}}
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case SlideLeft:
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coords = []Coord{{Row: c.Row, Col: c.Col - 1}}
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case SlideRight:
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coords = []Coord{{Row: c.Row, Col: c.Col + 1}}
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}
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for _, coord := range coords {
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neighborSymb, found := f.Cells[coord]
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if !found || neighborSymb == Tree {
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continue
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}
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neighbors = append(neighbors, coord)
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}
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return
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}
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func (f *Field) String() (result string) {
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result += "\n"
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for row := 0; row <= f.MaxRow; row++ {
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for col := 0; col <= f.MaxCol; col++ {
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if row == 0 && col == f.StartCol {
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result += "S"
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continue
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}
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if row == f.MaxRow && col == f.EndCol {
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result += "E"
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continue
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}
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symb := f.Cells[Coord{Row: row, Col: col}]
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result += string(symb)
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}
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result += "\n"
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}
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return
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}
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func ReadField(filename string) (result Field) {
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bytes, err := os.ReadFile(filename)
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if err != nil {
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panic(err)
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}
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lines := strings.Split(strings.TrimSpace(string(bytes)), "\n")
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result.MaxRow = len(lines) - 1
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result.MaxCol = len(lines[0]) - 1
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rows := make(map[Coord]CellType)
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for rowNum, row := range lines {
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for colNum, symb := range row {
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rows[Coord{Row: rowNum, Col: colNum}] = CellType(symb)
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if rowNum == 0 && symb == rune(Path) {
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result.StartCol = colNum
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}
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if rowNum == result.MaxRow && symb == rune(Path) {
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result.EndCol = colNum
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}
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}
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}
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result.Cells = rows
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return
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}
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