126 lines
3.0 KiB
Go
126 lines
3.0 KiB
Go
package reader
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import (
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"bufio"
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"fmt"
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"maze-solver/maze"
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"os"
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)
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type TextReader struct {
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PathChar, WallChar byte
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}
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func (r *TextReader) Read(filename string) (*maze.Maze, error) {
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nodesByCoord := make(map[maze.Coordinates]*maze.Node)
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var lines []string
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ret := &maze.Maze{}
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if _, err := os.Stat(filename); err != nil {
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return nil, err
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}
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file, err := os.Open(filename)
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if err != nil {
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return nil, err
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}
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scanner := bufio.NewScanner(file)
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scanner.Split(bufio.ScanLines)
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y := 0
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var line string
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for scanner.Scan() {
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line = scanner.Text()
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if len(lines) == 0 {
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lines = make([]string, 0, len(line))
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}
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for x := 1; x < len(line)-1; x++ {
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char := line[x]
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var left_char, right_char, above_char byte
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if y > 0 {
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left_char = line[x-1]
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right_char = line[x+1]
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above_char = lines[y-1][x]
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}
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// Parse first line to get entrance
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if y == 0 && char == r.PathChar {
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coords := maze.Coordinates{X: x, Y: y}
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node := maze.NewNode(coords)
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ret.Nodes = append(ret.Nodes, node)
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nodesByCoord[coords] = node
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continue
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}
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// Parse middle of the maze
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if y > 0 && char == r.PathChar &&
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(left_char == r.WallChar && right_char == r.PathChar ||
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left_char == r.PathChar && right_char == r.WallChar ||
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above_char == r.PathChar && (left_char == r.PathChar || right_char == r.PathChar)) {
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coords := maze.Coordinates{X: x, Y: y}
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node := maze.NewNode(coords)
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ret.Nodes = append(ret.Nodes, node)
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nodesByCoord[coords] = node
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r.lookupNeighbourAbove(&lines, node, &nodesByCoord)
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if left_char == r.PathChar && right_char == r.WallChar ||
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above_char == r.PathChar && (left_char == r.PathChar || right_char == r.PathChar) {
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r.lookupNeighbourLeft(&line, node, &nodesByCoord)
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}
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}
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}
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lines = append(lines, line)
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y++
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}
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y--
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// Parse last line to get exit
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for x, rune := range line {
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char := byte(rune)
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if char == r.PathChar {
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fmt.Printf("last line number: %v\n", y)
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coords := maze.Coordinates{X: x, Y: y}
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node := maze.NewNode(coords)
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r.lookupNeighbourAbove(&lines, node, &nodesByCoord)
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ret.Nodes = append(ret.Nodes, node)
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break
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}
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}
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return ret, nil
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}
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func (r *TextReader) lookupNeighbourAbove(lines *[]string, node *maze.Node, nodesByCoord *map[maze.Coordinates]*maze.Node) {
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for y := node.Coords.Y - 1; y >= 0; y-- {
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if (*lines)[y][node.Coords.X] == r.WallChar {
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break
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}
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neighbour, ok := (*nodesByCoord)[maze.Coordinates{X: node.Coords.X, Y: y}]
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if ok {
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node.Up = neighbour
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neighbour.Down = node
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}
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}
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}
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func (r *TextReader) lookupNeighbourLeft(line *string, node *maze.Node, nodesByCoord *map[maze.Coordinates]*maze.Node) {
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for x := node.Coords.X - 1; x > 0; x-- {
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if (*line)[x] == r.WallChar {
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panic(fmt.Sprintf("Found no node before wall while looking to the left at neighbours of node %v", node))
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}
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neighbour, ok := (*nodesByCoord)[maze.Coordinates{X: x, Y: node.Coords.Y}]
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if ok {
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node.Left = neighbour
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fmt.Printf("Setting left of %v to %v\n", node.Coords, neighbour.Coords)
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neighbour.Right = node
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break
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}
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}
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}
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