ISP542 · Fundamentals of AI · UiTM Perlis

Topic 4: Search — Interactive Visualizers

Search strategies stop being abstract when you can watch them run. These two visualizers animate uninformed search on a live tree: step through every action, watch the stack or queue fill and drain, then set your own Start and Goal and race the algorithm.

Open a visualizer More AI demos

Topic 4 (Search) — pick a strategy

Both apps open in a new tab. Click any node to set the Goal, then use Next Step to play the algorithm one action at a time.

Search tree rendered by the DFS Visualizer with node H marked as the current goal DFSStack Depth-First Search Visualizer Dives down one branch as far as it can before backtracking, driven by an explicit stack. Watch push, visit, pop and backtrack actions update the stack, traversal order and evaluation table. Open the DFS visualizer → Search tree rendered by the BFS Visualizer with the frontier expanding level by level BFSQueue Breadth-First Search Visualizer Explores the tree ring by ring from the Start node, driven by a queue (the frontier). Watch which nodes get enqueued, visited and closed — and when BFS finds the shortest path. Open the BFS visualizer →

How to use them in class

  • Predict first: with the tree visible, write down the order you expect the nodes to be visited — then step through and compare.
  • Same tree, two strategies: run DFS and BFS on the identical Start/Goal and contrast the visited order and the fringe contents.
  • Depth vs completeness: see why DFS can go off down a wrong branch forever, while BFS always finds a shallowest solution.