Dijkstra Algorithm Visualization Tool

This interactive web application allows users to visualize and understand Dijkstra's algorithm for finding the shortest path in a graph. Users can create nodes, establish connections between them with custom weights, and run the algorithm to find the shortest paths.

Features

• Interactive Graph Creation: Click on the canvas to create nodes and connect them
• Custom Connection Weights: Assign numeric weights to each connection
• Customizable Starting Point: Right-click any node to set it as the starting point for the algorithm
• Real-time Calculation: Calculate shortest paths from the selected starting node to all other nodes
• Edit and Modify: Clear the last step or reset the entire graph as needed

How to Use

Creating the Graph

1. Create Nodes:

   • Click anywhere on the canvas to create a node
   • Each node is automatically assigned a sequential number

2. Connect Nodes:

   • Click on a source node first (it will highlight in green)
   • Then click on a destination node to create a connection
   • An input field will appear where you can set the weight of the connection

3. Set Connection Weights:

   • Enter positive numbers in the input fields below the canvas
   • Each input represents the cost/weight of moving from one node to another

4. Choose Starting Point:

   • By default, node 0 is the starting point
   • Right-click on any node to set it as the new starting point
   • The selected starting point will be highlighted in blue

Running the Algorithm

1. Click the "Calculate Shortest Path" button to run Dijkstra's algorithm
2. The results will display below the canvas, showing:
   • The shortest path from the starting node to each other node
   • The total distance (sum of weights) for each path
   • "No path available" message for unreachable nodes

Editing the Graph

• Clear Last Step: Remove the most recently added node or connection
• Clear All: Reset the entire canvas and start over

Technical Information

The application implements Dijkstra's algorithm to find the shortest paths in a weighted directed graph. The algorithm:

1. Initializes distances from the source to all other nodes as infinity
2. Sets distance to the source node as 0
3. Iteratively finds the unvisited node with the smallest distance
4. Updates distances to all neighboring nodes if a shorter path is found
5. Continues until all nodes are visited or unreachable nodes remain

Requirements

• A modern web browser with JavaScript enabled
• No external dependencies required

Limitations

• Only supports directed graphs (connections have a specific direction)
• Connection weights must be positive numbers (negative weights are not supported)

Troubleshooting

• If connections are not displaying correctly, ensure you've entered valid weights
• Red highlighted inputs indicate invalid values that need correction
• For optimal performance, limit graphs to a reasonable number of nodes (< 50)