Data commit

Task/Sokoban/Go/sokoban.go

@@ -0,0 +1,117 @@
+package main
+
+import (
+    "fmt"
+    "strings"
+)
+
+func main() {
+    level := `
+#######
+#     #
+#     #
+#. #  #
+#. $$ #
+#.$$  #
+#.#  @#
+#######`
+    fmt.Printf("level:%s\n", level)
+    fmt.Printf("solution:\n%s\n", solve(level))
+}
+
+func solve(board string) string {
+    buffer = make([]byte, len(board))
+    width := strings.Index(board[1:], "\n") + 1
+    dirs := []struct {
+        move, push string
+        dPos       int
+    }{
+        {"u", "U", -width},
+        {"r", "R", 1},
+        {"d", "D", width},
+        {"l", "L", -1},
+    }
+    visited := map[string]bool{board: true}
+    open := []state{state{board, "", strings.Index(board, "@")}}
+    for len(open) > 0 {
+        s1 := &open[0]
+        open = open[1:]
+        for _, dir := range dirs {
+            var newBoard, newSol string
+            newPos := s1.pos + dir.dPos
+            switch s1.board[newPos] {
+            case '$', '*':
+                newBoard = s1.push(dir.dPos)
+                if newBoard == "" || visited[newBoard] {
+                    continue
+                }
+                newSol = s1.cSol + dir.push
+                if strings.IndexAny(newBoard, ".+") < 0 {
+                    return newSol
+                }
+            case ' ', '.':
+                newBoard = s1.move(dir.dPos)
+                if visited[newBoard] {
+                    continue
+                }
+                newSol = s1.cSol + dir.move
+            default:
+                continue
+            }
+            open = append(open, state{newBoard, newSol, newPos})
+            visited[newBoard] = true
+        }
+    }
+    return "No solution"
+}
+
+type state struct {
+    board string
+    cSol  string
+    pos   int
+}
+
+var buffer []byte
+
+func (s *state) move(dPos int) string {
+    copy(buffer, s.board)
+    if buffer[s.pos] == '@' {
+        buffer[s.pos] = ' '
+    } else {
+        buffer[s.pos] = '.'
+    }
+    newPos := s.pos + dPos
+    if buffer[newPos] == ' ' {
+        buffer[newPos] = '@'
+    } else {
+        buffer[newPos] = '+'
+    }
+    return string(buffer)
+}
+
+func (s *state) push(dPos int) string {
+    newPos := s.pos + dPos
+    boxPos := newPos + dPos
+    switch s.board[boxPos] {
+    case ' ', '.':
+    default:
+        return ""
+    }
+    copy(buffer, s.board)
+    if buffer[s.pos] == '@' {
+        buffer[s.pos] = ' '
+    } else {
+        buffer[s.pos] = '.'
+    }
+    if buffer[newPos] == '$' {
+        buffer[newPos] = '@'
+    } else {
+        buffer[newPos] = '+'
+    }
+    if buffer[boxPos] == ' ' {
+        buffer[boxPos] = '$'
+    } else {
+        buffer[boxPos] = '*'
+    }
+    return string(buffer)
+}