Hamiltonian path & cycle checker
Check whether a graph has a Hamiltonian path (visits every vertex once) or a Hamiltonian cycle (also returns to the start). Enter an edge list, pick directed or undirected, and an exhaustive backtracking search either returns a concrete path and cycle or proves that none exists. Capped at 12 vertices for speed.
Related tools
All Discrete maths & graphs tools →Open Hamiltonian path & cycle checker and you get an answer straight away, with no account to create. Its place is under Discrete maths & graphs; Dijkstra shortest path calculator and Bitwise Calculator answer the questions closest to this one.
How to use it
- Open the tool — no signup or install needed.
- Enter your input or adjust the available options.
- Get your result instantly, then copy or download it.
Frequently asked questions
What is Hamiltonian path & cycle checker?
Check whether a graph has a Hamiltonian path (visits every vertex once) or a Hamiltonian cycle (also returns to the start). Enter an edge list, pick directed or undirected, and an exhaustive backtracking search either returns a concrete path and cycle or proves that none exists. Capped at 12 vertices for speed.
What does a concrete case look like?
Cₙ ✓ · K₁,₃ ✗ — the tool shows every step in between, not just the final figure.
When would I actually use this?
Anything modelled as points and connections: a shortest route, a network's capacity, a schedule with dependencies, or a circuit reduced to its logic.
What is the most common mistake?
Assuming a shortest path stays shortest when a weight changes sign. Negative edges break the greedy argument Dijkstra rests on, and the algorithm returns a confident wrong answer rather than an error.
How is Hamiltonian path & cycle checker different from Dijkstra shortest path calculator?
They sit next to each other but answer different questions: Dijkstra shortest path calculator is the one to open when you need it to enter a weighted graph as edges ("A, B, 4" per line) and a source node: Dijkstra's algorithm returns the shortest distance and the exact path from the source to every reachable vertex. Works for directed or undirected graphs, accepts many edge formats, and flags unreachable vertices — ideal for routing, networks and pathfinding. Pick whichever matches what you're starting from — both are free.
Where do the figures come from?
The algorithms are the textbook ones and their results are exact for the graph you enter. What varies is cost: several of these problems have no known efficient solution, so large inputs are answered by heuristic and the tool says when that is the case.