diff --git a/23.jl b/23.jl
new file mode 100644
index 0000000..4179885
--- /dev/null
+++ b/23.jl
@@ -0,0 +1,137 @@
+function winp(hall, rooms)
+    all(map(==('A'), rooms[1])) && all(map(==('B'), rooms[2])) && all(map(==('C'), rooms[3])) && all(map(==('D'), rooms[4]))
+end
+
+function moveroomp(hall, rooms, room, pos, letter)
+    # check empty path
+    if pos > room * 2 + 1
+        if !all(map(==(' '), hall[(room * 2 + 1):(pos-1)]))
+            return false
+        end
+    else
+        if !all(map(==(' '), hall[(pos+1):(room * 2 + 1)]))
+            return false
+        end
+    end
+    # check place in room
+    if rooms[room][1] != ' '
+        return false
+    end
+    # check other is same
+    if any(map(i->rooms[room][i] != ' ' && rooms[room][i] != letter, 2:length(rooms[room])))
+        return false
+    end
+    true
+end
+
+function makemove(hall, rooms, i, letter, cost, stepcost, room)
+    h = copy(hall)
+    r = deepcopy(rooms)
+    h[i] = ' '
+    lastempty = reduce(max, filter(i->r[room][i] == ' ', 1:length(r[room])))
+    c = cost + (abs(i - (room*2+1)) + lastempty) * stepcost;
+    r[room][lastempty] = letter
+    h, r, c
+end
+
+function makemoves(rooms, hall, room, cost)
+    if all(map(==(' '), rooms[room]))
+        return []
+    end
+    if all(map(letter->((codepoint(letter)-0x40)==room || letter == ' '), rooms[room]))
+        return []
+    end
+    up = (room*2+1):length(hall)
+    down = reverse(1:(room*2+1))
+    targets = filter(i->!(i in [3,5,7,9]),
+                     union(Iterators.takewhile(i->hall[i]==' ', up),
+                           Iterators.takewhile(i->hall[i]==' ', down)))
+    firstnonempty = reduce(min, filter(i->rooms[room][i] != ' ', 1:length(rooms[room])))
+    map(targets) do target
+        h = copy(hall)
+        r = deepcopy(rooms)
+        h[target] = rooms[room][firstnonempty]
+        c = cost + (abs(target - (room*2+1)) + firstnonempty) * 10^(codepoint(h[target])-0x41);
+        r[room][firstnonempty] = ' '
+        h, r, c
+    end
+end
+
+function legalmoves(hall, rooms, cost)
+    moves = []
+    for i in 1:length(hall)
+        if hall[i] == ' '
+            continue
+        end
+        if hall[i] == 'A' && moveroomp(hall, rooms, 1, i, 'A')
+            push!(moves, makemove(hall, rooms, i, 'A', cost, 1, 1))
+            continue
+        end
+        if hall[i] == 'B' && moveroomp(hall, rooms, 2, i, 'B')
+            push!(moves, makemove(hall, rooms, i, 'B', cost, 10, 2))
+            continue
+        end
+        if hall[i] == 'C' && moveroomp(hall, rooms, 3, i, 'C')
+            push!(moves, makemove(hall, rooms, i, 'C', cost, 100, 3))
+            continue
+        end
+        if hall[i] == 'D' && moveroomp(hall, rooms, 4, i, 'D')
+            push!(moves, makemove(hall, rooms, i, 'D', cost, 1000, 4))
+        end
+    end
+    for i in 1:4
+        append!(moves, makemoves(rooms, hall, i, cost))
+    end
+    moves
+end
+
+function cheapsort(hall, rooms)
+    costmin = typemax(Int64)
+    visited = Dict()
+    moves = legalmoves(hall, rooms, 0)
+
+    while length(moves) > 0
+
+        sort!(moves, by=m->m[3])
+
+        while length(moves) > 0 && last(moves)[3] >= costmin
+            pop!(moves)
+        end
+        if length(moves) == 0
+            break
+        end
+
+        move = pop!(moves)
+        if haskey(visited, move)
+            continue
+        end
+
+        if move[3] >= costmin
+            break
+        end
+        if winp(move[1], move[2])
+            println(length(moves), ' ', move[3], ' ', loops)
+            costmin = move[3]
+            continue
+        end
+        append!(moves, legalmoves(move[1], move[2], move[3]))
+        visited[move] = true
+    end
+    costmin
+end
+
+function solution23_1()
+    hall = fill(' ', 11)
+    rooms = [['B', 'A'], ['C', 'D'], ['B', 'C'], ['D', 'A']]
+#    rooms = [['A', 'C'], ['D', 'D'], ['A', 'B'], ['C', 'B']]
+    cheapsort(hall, rooms)
+end
+
+function solution23_2()
+    hall = fill(' ', 11)
+    rooms = [['B', 'D', 'D', 'A'], ['C', 'C', 'B', 'D'], ['B', 'B', 'A', 'C'], ['D', 'A', 'C', 'A']]
+#    rooms = [['A', 'D', 'D', 'C'], ['D', 'C', 'B', 'D'], ['A', 'B', 'A', 'B'], ['C', 'A', 'C', 'B']]
+    cheapsort(hall, rooms)
+end
+
+solution23_2()