instanceqa194
resultexact 0.00%
time< 1 min
code100× less
days17
Solver Story
8Z-RP · TSP as Compression
Full research · empirical proof · GPU · DCC evolution
17×8
sensors × laws
40/157 exact
phase transition
Data Lab
Arena Lab · MDL Decides
17 sensors · 8 laws · ranking inversion · hierarchical v1.6
Interactive Map
qa194 Tour · Qatar
194 cities · Leaflet · gold tour · crossing detection

8Z Research Program · AIM³ Institute · Live Computation

nu3496
Impossible
Made Routine

Nicaragua · 3,496 real locations

Before the year 2000, this computation was science fiction. Today it runs on a laptop.

3,496 real locations across Nicaragua. A search space larger than the number of atoms in the observable universe — by a factor that itself has over 10,000 digits. Our solver, built from pre-1980 mathematics and ~100 KB of Python, finds a solution within 1.241% of the known optimum at t=61h. No commercial software. No supercomputer. No external dependencies. Just math and a new idea.

n = 3,496 cities optimal = 96,132 best gap 1.241% DCC v2 adaptive ~100 KB Python zero dependencies t = 61h snapshot
The scale of the problem

How Many Routes Exist?

For a Travelling Salesman Problem with n cities, the number of distinct possible routes is (n−1)! ÷ 2. For n = 3,496 that is (3,495)! ÷ 2. Here is what that number actually looks like — all 10,869 digits of it:

Possible routes for Nicaragua (nu3496) — (3,495)! ÷ 2 10,869 digits · scroll to see all · leading digits are exact

Brute force at 10¹² routes/sec

Would need 1010,856 years

The observable universe is ~14 billion years old. You would need that many more universes of time just to begin to sample the space.

Atoms in the universe

~1080 — 81 digits

Our search space is larger by a factor whose exponent has over 10,000 digits. There is no physical analogy adequate to close this gap.

What we actually do

Navigate, don't enumerate

We never look at most routes. Smart moves + adaptive DCC governance follow improvement gradients, escaping local optima without random thrashing.

Our result at t = 50.6h

1.241% from optimal

Out of a 10,869-digit search space, we land within 1.241% of the best known solution. On a laptop. In slow Python. With math invented before 1980.

The algorithms

Built on Half-Century-Old Mathematics

Every optimization move in our solver was invented before 1980 — most before personal computers existed. We use no machine learning, no proprietary techniques, no black boxes. Pure classical combinatorial mathematics, directed by one new idea: the DCC governor.

1930s

TSP formally posed

The Travelling Salesman Problem is stated rigorously. No efficient algorithm is known. It will eventually become the defining NP-hard benchmark — the problem against which all solvers are judged. It remains unsolved in the general case to this day.

1954

Greedy construction (nearest-neighbour)

Build a tour by repeatedly visiting the closest unvisited city. Simple, fast, not optimal — but a strong starting point. This is our initialization strategy, and it beats every space-filling curve we tested on nu3496 (greedy: 103,064 after 2-opt vs hilbert best: 107,262).

1958

2-opt — Croes, 1958

Remove two edges from the tour, reconnect in the only other possible way. If shorter, keep it. Repeat until no improvement. Invented 67 years ago. Still the most effective local search primitive in practice. Our Rust-accelerated 2-opt inner loop runs ~100× faster — but the algorithm is bit-for-bit identical to Croes's original.

1973

Lin–Kernighan, Bell Labs, 1973

The theoretical framework for sequential k-opt moves. Published by Shen Lin and Brian Kernighan. Established the intellectual foundation for all modern TSP local search. Still cited in every serious TSP paper written today.

1976

Or-opt — I. Or, 1976

Relocate a chain of 1, 2, or 3 consecutive cities to a better position elsewhere in the tour. Finer-grained than 2-opt — makes surgical improvements where 2-opt cannot. In our nu3496 runs, or-opt-1 and or-opt-3 produce more wins than double-bridge by a wide margin. Published 49 years ago. Decisive in 2025.

2024–26

DCC — Digital Claustrum Controller (new)

The one thing we invented. An adaptive governor that decides which classical move to apply, when to escalate intensity, and how to escape stagnation without collapsing. The underlying moves are 50–70 years old. The DCC is what orchestrates them intelligently at scale, without human tuning, and self-heals when workers get stuck.

The punchline

We took algorithms invented between 1954 and 1976, added a new adaptive governor inspired by neuroscience, wrapped the whole thing in ~100 KB of Python with zero external dependencies, and achieved results on a 3,496-city instance that would have required a supercomputer and months of runtime in the 1990s — if it had been attempted at all. The math is older than most personal computers. The results are state-of-the-art for our hardware class.

Context

Us vs. The Field

The gold standard for TSP is Concorde — a solver built over decades by world-class research teams at Princeton, Waterloo, and Rice. Here is what separates us:

Concorde & commercial solvers
Codebase: millions of lines of C, developed over 30+ years
Dependencies: CPLEX LP solver (commercial, ~$50,000/yr license), specialized cutting-plane libraries, LP relaxation infrastructure
Team: decades of work by PhD mathematicians and world-class algorithm researchers at top universities
Method: branch & bound + LP relaxation + Gomory cuts — guarantees exact optimal but requires massive mathematical and computational infrastructure
Hardware: cluster computing, dedicated servers, sometimes years of CPU time
Output: provably optimal (eventually)
vs
8Z-RP v2.5
Codebase: ~100 KB of Python. One file. Readable by any programmer.
Dependencies: zero for the core algorithm. One optional Rust extension for inner-loop speed (PyO3/maturin, ~200 lines).
Team: one researcher (AIM³ Institute, Ljubljana) + AI collaboration
Method: classical moves from 1958–1976, directed by DCC v2 adaptive governor. No LP, no cutting planes, no approximation theorems.
Hardware: consumer laptop (Razer Blade, 16 cores, RTX GPU, Windows 11)
Output: 1.241% from optimal at t=61h and still improving

What this comparison means for P vs NP research

Concorde proves optimality — but needs an entire mathematical edifice to do it. We don't prove optimality. We show something different: that a lightweight adaptive system, built from mathematical primitives invented before the moon landing, can navigate a 10,869-digit search space and land within 1.241% of optimal. The efficiency of navigation is the empirical signal. How does a small system find good solutions so reliably in a space this large? That question is the research.

Perspective

50 Hours Is Not Slow. It Is Extraordinary.

Before 1990

This problem was science fiction

In the 1980s, solving a 3,496-city TSP instance to within 2% of optimal was not a research goal — it was outside the conceptual horizon. The computational theory for large-scale heuristic TSP didn't exist. Available hardware was millions of times slower than a modern laptop.

1990s — with supercomputers

Still not realistic

Early 1990s supercomputers ran at megahertz clock speeds. Instances above n=1,000 were considered "large." Researchers published papers celebrating solutions for n=500. A 3,496-city instance with a sub-2% gap bound was years away even for the best-funded teams in the world.

Today — consumer hardware

61h to 1.241% gap

A consumer laptop, available for €2,000. Python, available for free. Math invented before the first moon landing. One new idea. The same computation that was impossible in 1990 now runs while you sleep — on hardware you can buy in a store.

"The 50 hours are not a measure of slowness. They are a measure of the problem's true depth — and our ability to navigate it with almost nothing."

For full context: Concorde on very large instances

Concorde — the most powerful TSP solver ever built, backed by decades of research and requiring commercial LP solver licenses — needed over 136 CPU-years to prove the optimal solution for the 85,900-city pla85900 instance (2006). That is the best team in the world, unlimited compute, decades of work. We are not Concorde. We are not trying to be. We are a 100 KB Python file finding near-optimal solutions to a 3,496-city instance in 50 hours on a single laptop. This comparison is not embarrassing. It is extraordinary.

Live snapshot · t = 61h

Where We Stand

Third checkpoint. t≈61h (March 18 08:50 → March 20 22:03). Fleet of 14 workers, all active. Meta-DCC: 1,030 snapshots, 34 meta-steps. Fleet convergence reached — all workers within 0.022% of each other. Tightest spread since the run began.

61h
Elapsed
168h budget · 36.3% used
1.241%
Best gap
W13 · 97,325 / 96,132
14/14
Workers active
all improving
1.253%
Fleet avg gap
W13–W12 spread: 0.022%
~15%
Move budget used
~26,000–28,000/worker
~1.10–1.15%
Projected gap t=168h
sub-1% needs 3-opt/LK
WorkerGap barGap %Best tourStatus

Fleet convergence — shared basin found

All 14 workers converged to within 0.022% (21 tour units) of each other — the tightest spread since the run began. Previous spread at t=50.6h was >1.2%. The fleet has found a shared local basin. DCC v2 self-healing and Meta-DCC fleet monitoring both contributed.

Timeline: 0.379% improvement in 10h

t≈50.6h: W5 at 1.620% (previous leader).
t≈61h: W13 at 1.241% — improvement of 0.379% in ~10h. W13 was not even in top-3 at t=50.6h. A new worker emerged as leader through sustained DCC-governed search.

Fleet convergence diagnosis — what comes next

The fleet has found a shared local basin. Further improvement to t=168h likely reaches ~1.10–1.15%. Sub-1% is unlikely without:

  1. Algorithmic lever: 3-opt or Lin-Kernighan moves (not yet implemented). These can escape basins that 2-opt and or-opt cannot.
  2. Better governance: Arena Lab shows gravity+ADSR and LZ_dual+PI outperform the current LZ_binary+BB on uy734 (n=734). At n=3496, the classic sensor is even more limited — the binary improvement stream is too sparse at this scale.
  3. Hierarchical DCC: Partition 3,496 cities into ~17 clusters of ~200. Govern each cluster with geometric sensors (their optimal scale, where they find exact optimal). Stitch cluster solutions into a global tour.
Configuration

What Is Actually Running

python 8zrp_v2.5.py solve nu3496.tsp \ --strategy arena \ --dcc-version 2 \ --moves-per-n 50 \ --workers 10 \ --kicks double-bridge \ --max-hours 168 \ --out nu3496_max [2-opt backend: rust (auto-detected)] [resume: W0@m7884 ... W9@m8982 ] n=3,496 | optimal=96,132 total moves=174,800 per worker
# entire solver (Python core) wc -c 8zrp_v2.5.py ~100,000 bytes (~100 KB) # external pip dependencies for core (none) # zero, stdlib only # optional speed extension zrp2opt # Rust 2-opt ~100x faster

Hardware — consumer laptop

Razer Blade Advanced 2021

16 CPU cores (14 in use for workers). Consumer RTX GPU. Windows 11. Standard off-the-shelf hardware. Nothing purpose-built, nothing rented from a cloud provider.

The Rust acceleration

Speed without new math

The 2-opt inner loop is accelerated via a small Rust extension (~200 lines, PyO3/maturin). ~100× speedup for that one loop. The algorithm itself — the logic, the moves, the math — is identical to Croes 1958. We added speed. The intelligence remains in the DCC.