Interactive DSA and system design

Learn complex engineering ideas by watching them move.

32stepsO((V + E) log V)averageO(V)space

Graphs lab

Dijkstra Shortest Path Tree (SPT)

Step 1 / 32

FIFO Queue

FrontEmptyBack

Recursion Stack

Empty

Min-Priority Queue

Adist: 0Bdist: ∞Cdist: ∞Ddist: ∞Edist: ∞Fdist: ∞

Visiting Active Node Visited Shortest Path

Animation speed

Space play / pause←→ stepR reset

Current operation

Initialize Dijkstra's

Set start node A's distance to 0, and all other node distances to Infinity (∞). Add all nodes to the priority queue.

Algorithm state

AStart NodeA(d=0), B(d=∞), C(d=∞), D(d=∞), E(d=∞), F(d=∞)Priority Queue

Select Start Node

Click a node to restart the graph traversal from that starting point.

Complexity notes

O((V + E) log V)averageO(V²)worstO(V)spaceNostable

Synced code trace

function Dijkstra(graph, start) {  const dist = {}, pq = new MinPriorityQueue();  dist[start] = 0;  pq.insert(start, 0);  while (!pq.isEmpty()) {    const u = pq.extractMin();    for (const { v, weight } of graph[u]) {      const alt = dist[u] + weight;      if (alt < dist[v]) {        dist[v] = alt;        pq.decreaseKey(v, alt);      }    }  }}

Interactive Notes

✓ Notes are saved automatically and persist per step.