Data commit

Task/Sokoban/Julia/sokoban.julia

@@ -0,0 +1,93 @@
+struct BoardState
+    board::String
+    csol::String
+    position::Int
+end
+
+function move(s::BoardState, dpos)
+    buffer = Vector{UInt8}(deepcopy(s.board))
+    if s.board[s.position] == '@'
+        buffer[s.position] = ' '
+    else
+        buffer[s.position] = '.'
+    end
+    newpos = s.position + dpos
+    if s.board[newpos] == ' '
+        buffer[newpos] = '@'
+    else
+        buffer[newpos] = '+'
+    end
+    String(buffer)
+end
+
+function push(s::BoardState, dpos)
+    newpos = s.position + dpos
+    boxpos = newpos + dpos
+    if s.board[boxpos] != ' ' && s.board[boxpos] != '.'
+        return ""
+    end
+    buffer = Vector{UInt8}(deepcopy(s.board))
+    if s.board[s.position] == '@'
+        buffer[s.position] = ' '
+    else
+        buffer[s.position] = '.'
+    end
+    if s.board[newpos] == '$'
+        buffer[newpos] = '@'
+    else
+        buffer[newpos] = '+'
+    end
+    if s.board[boxpos] == ' '
+        buffer[boxpos] = '$'
+    else
+        buffer[boxpos] = '*'
+    end
+    String(buffer)
+end
+
+function solve(board)
+    width = findfirst("\n", board[2:end])[1] + 1
+    dopt = (u = -width, l = -1, d = width, r = 1)
+    visited = Dict(board => true)
+    open::Vector{BoardState} = [BoardState(board, "", findfirst("@", board)[1])]
+    while length(open) > 0
+        s1 = open[1]
+        open = open[2:end]
+        for dir in keys(dopt)
+            newpos = s1.position + dopt[dir]
+            x = s1.board[newpos]
+            if x == '$' || x == '*'
+                newboard = push(s1, dopt[dir])
+                if newboard == "" || haskey(visited, newboard)
+                    continue
+                end
+                newsol = s1.csol * uppercase(string(dir))
+                if findfirst(r"[\.\+]", newboard) ==  nothing
+                    return newsol
+                end
+            elseif x == ' ' || x == '.'
+                newboard = move(s1, dopt[dir])
+                if haskey(visited, newboard)
+                    continue
+                end
+                newsol = s1.csol * string(dir)
+            else
+                continue
+            end
+            open = push!(open, BoardState(newboard, newsol, newpos))
+            visited[newboard] = true
+        end
+    end
+    "No solution" # we should only get here if no solution to the sokoban
+end
+
+const testlevel = strip(raw"""
+#######
+#     #
+#     #
+#. #  #
+#. $$ #
+#.$$  #
+#.#  @#
+#######""")
+println("For sokoban level:\n$testlevel\n...solution is :\n$(solve(testlevel))")