Made by Bonelli Labs

Is finding as easy as checking?

P vs NP asks: if we can check a solution fast, can we also find one fast?

Millennium Prize Problem

P

Problems solvable quickly (polynomial time).

NP

Solutions verifiable quickly.

NP-Complete

The "hardest" problems in NP — a fast solution to one solves them all.

Why it matters

The question of whether efficiently checkable problems are also efficiently solvable controls the frontier of algorithms and security. P = NP would collapse verification into search and unsettle cryptography; P ≠ NP would certify intractability and justify the widespread use of heuristics, parameterization, and approximation.

NP-Complete hard hubs Logistics / Routing Chip Layout / EDA Biology Cryptography

Core intuitions

NP consists of problems with polynomial‑length certificates verifiable in polynomial time; P is the subclass solvable outright. Polynomial‑time many‑one reductions compare difficulty, and NP‑complete problems are maximal under this ordering: solving one in polynomial time collapses NP to P. The lack of such algorithms motivates approximation, parameterized methods, and average‑case analysis.

NP P (efficiently solvable) verify = solve cert verify ≪ search NP‑C complete A ≤p B B ≤p C A B C

Reductions gallery

Each clause becomes a group of literal-nodes; connect non-conflicting literals across clauses. A k-clique corresponds to a satisfying assignment (k = number of clauses).

Variables: x1..x5
Graph (nodes and edges)

              

Interactive demos

SAT Playground (tiny CNF)

Enter a small CNF formula and toggle variable assignments to see if it satisfies.

Allowed: x1..x9, ! (not), | (or), & (and), parentheses

Result

Subset Sum Verifier

Provide numbers and a target. We check if any subset matches the target.

Result

3-Coloring (small graph)

Click nodes to cycle colors. No edge should connect same-colored nodes.

Status

Reduction Quiz

Match the reduction. Quick practice.

Further resources

Further resources

Advanced Labs

Reduction Lab (Drag-and-Drop Pipeline)

Build a reduction pipeline and see size blowup and certificate mappings.

Scaling Wall (Instance Size vs Time)

Value: 12
Value: 50%

Approximation Game (Greedy vs Optimal)

Compare greedy and exact solutions on tiny instances.

Value: 8

Parameterized Complexity Playground

Value: 12
Value: 4

Fine-Grained Complexity Stopwatch

Explore hypothetical time laws under ETH/SETH style assumptions.

Value: 3
Value: 30