How the board works
The board is a tight rectangle of unequal blocks. Cao Cao is the large block, guards and soldiers fill the lanes, and the empty cells are the only places where motion can begin.
Eastern Puzzle ArchiveAlgorithmic puzzle-system sample / Huarong Dao
A sliding-block story becomes a search problem.
Huarong Dao is the first algorithmic puzzle-system sample in this maker-run resource. It sits beside Tangram and Nine Linked Rings because the first shelf is about shape, sequence, and search: three ways old puzzle objects become AI-readable puzzle systems.
Sliding blocksState-space searchSource pages 205-289
Read the system
Start with the board before the algorithm.
The story makes the puzzle memorable, but the board is what makes it reusable. Once the pieces, empty cells, and legal slides are clear, Huarong Dao becomes a compact model for search, constraint, and path finding.
What the sources can support
The source material supports Huarong Dao as a Chinese sliding-block puzzle with a Three Kingdoms story frame. Its exact toy history should stay cautious, especially when comparing it with other sliding-block traditions.
What AI and search can study
Every legal board layout is a state. A solver can generate legal moves, compare paths, measure dead ends, and ask why one arrangement opens space while another traps the board.
Try the board
Watch board states become a search path.
Use the board to test the first moves yourself. The replay turns each arrangement into a node and each legal slide into an edge, which is exactly the kind of structure a search algorithm can reason about.
Exit
State 1 of 6
Opening node
Start from a crowded board with two empty cells near the exit.
A solver reads this entire layout as one node in the graph, not as ten separate pieces.Challenge status
Make the lower pocket
Move S1 into the lower pocket.
- Status
- Challenge in progress
- Move count
- 0
Move S1 down into row 5. The pocket opens only after the soldier leaves row 4.
No block selected
Select a block to see legal slides from this board state.
Hidden mathematics
Every layout is a node.
Once each legal board position becomes a state, a solution is a path through a graph. Shorter paths, dead ends, and layout families become questions of search, not just questions of patience.
State space
Read every legal board arrangement as one node in a graph.
Search
Move from state to state until the large block reaches the exit.
Optimization
Compare 100-step, 84-step, and shorter routes as different paths.
Huarong Dao library
Read the board as a search problem.
Huarong Dao and Sliding-Block Search
A source-backed guide to Huarong Dao as a Chinese sliding-block puzzle and a natural route into state-space exploration.
Source pages 205-289Read the search guideNext challenge
Move S1 into the lower pocket.
The next product step is a short challenge layer on top of the current board: select S1, move it into the lower pocket, count the move, and show why that tiny shift creates room for later search. This keeps the task understandable before asking visitors to solve the whole puzzle.