Feature/tsp solvers

Project.toml

@@ -0,0 +1,10 @@
+[deps]
+HiGHS = "87dc4568-4c63-4d18-b0c0-bb2238e4078b"
+Hygese = "0672f53d-ad77-409a-bbb3-4bc94f101f4b"
+JuMP = "4076af6c-e467-56ae-b986-b466b2749572"
+LKH = "294deba0-74fa-42c9-af84-c3834b01fefc"
+Metaheuristics = "bcdb8e00-2c21-11e9-3065-2b553b22f898"
+Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
+Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
+TSPLIB = "b1c258e7-59ae-4b06-a547-f10871db1548"
+TravelingSalesmanHeuristics = "8c8f4381-2cdd-507c-846c-be2bcff6f45f"

README.md

@@ -5,7 +5,26 @@ The [Travelling Salesman Problem (TSP)](https://en.m.wikipedia.org/wiki/Travelli
 * An efficient solver, which uses the [Miller-Tucker-Zemlin Encoding](https://phabe.ch/2021/09/19/tsp-subtour-elimination-by-miller-tucker-zemlin-constraint/) to translate TSP into an Integer Programming problem and solves that with the commercial state-of-the-art solver Gurobi
 * A standalone solver which implements the [Held-Karp algorithm](https://en.wikipedia.org/wiki/Held%E2%80%93Karp_algorithm) to solve TSP with dynamic programming
 * A simple branch-and-bound solver for educational purposes, who can prune backtracking branches as soon as their lower bound is bigger than the current maximum
+* [Concorde](http://www.math.uwaterloo.ca/tsp/concorde.html) State-of-the-art exact TSP solver using cutting planes
+* [LKH-3](http://webhotel4.ruc.dk/~keld/research/LKH-3/) Lin-Kernighan Heuristic, one of the best TSP heuristics
+* [Hygese](https://github.com/chkwon/Hygese.jl) Hybrid Genetic Search for CVRP/TSP
+
+## Quick Start
+
+```bash
+# 1. Run setup (installs all Julia packages)
+julia setup.jl
+
+# 2. Run the benchmark
+julia --project=. main.jl
+```
+
+## Requirements
+
+- **Julia 1.9+** (tested with 1.12)
+- **Concorde binary** (for optimal solutions on larger instances)
+
 
 Using `benchmark()`, one can compare the performances on the [TSPLIB95 Dataset](http://comopt.ifi.uni-heidelberg.de/software/TSPLIB95/). `benchmark.log` also provides pre-recorded results measured with an Intel i9-10980HK and 32 GB of memory.
 
-(c) Mia Müßig
+(c) Mia Müßig

concorde-solver.jl

@@ -0,0 +1,119 @@
+# Concorde TSP Solver - CLI Wrapper
+# Calls the system-installed Concorde binary directly
+
+"""
+    solve_concorde(tsp, timeout)
+
+Solves a TSPLIB instance using the Concorde solver via command-line interface.
+
+This wrapper calls the Concorde binary directly, avoiding the need for the
+Concorde.jl package to build its own copy.
+
+Requires: Concorde binary installed (e.g., at ~/.local/bin/concorde)
+
+# Arguments
+- `tsp`: the TSPLIB instance (from TSPLIB.jl)
+- `timeout`: solver timeout in seconds
+"""
+function solve_concorde(tsp, timeout::Int=60)
+  # Find concorde binary
+  concorde_path = get(ENV, "CONCORDE_PATH", expanduser("~/.local/bin/concorde"))
+
+  if !isfile(concorde_path)
+    # Try to find in PATH
+    try
+      concorde_path = strip(read(`which concorde`, String))
+    catch
+      concorde_path = ""
+    end
+    if isempty(concorde_path) || !isfile(concorde_path)
+      println("Concorde binary not found. Install from http://www.math.uwaterloo.ca/tsp/concorde/")
+      return nothing, nothing
+    end
+  end
+
+  n = tsp.dimension
+
+  # Create temporary directory for working files
+  mktempdir() do tmpdir
+    # Write distance matrix in TSPLIB format
+    tsp_file = joinpath(tmpdir, "problem.tsp")
+    sol_file = joinpath(tmpdir, "problem.sol")
+
+    open(tsp_file, "w") do f
+      println(f, "NAME: problem")
+      println(f, "TYPE: TSP")
+      println(f, "DIMENSION: $n")
+      println(f, "EDGE_WEIGHT_TYPE: EXPLICIT")
+      println(f, "EDGE_WEIGHT_FORMAT: FULL_MATRIX")
+      println(f, "EDGE_WEIGHT_SECTION")
+
+      for i in 1:n
+        row = String[]
+        for j in 1:n
+          push!(row, string(round(Int, tsp.weights[i, j])))
+        end
+        println(f, join(row, " "))
+      end
+      println(f, "EOF")
+    end
+
+    try
+      # Run concorde FROM the temp directory so it writes files there
+      # Use -x to clean up intermediate files
+      cmd = Cmd(`$concorde_path -x -o problem.sol problem.tsp`, dir=tmpdir)
+
+      t_start = time()
+      proc = run(pipeline(cmd, stdout=devnull, stderr=devnull), wait=false)
+
+      deadline = time() + timeout
+      while process_running(proc) && time() < deadline
+        sleep(0.1)
+      end
+
+      if process_running(proc)
+        kill(proc)
+        return nothing, nothing
+      end
+
+      elapsed = time() - t_start
+
+      if !isfile(sol_file)
+        println("Concorde did not produce a solution file")
+        return nothing, nothing
+      end
+
+      # Parse solution file to get tour
+      lines = readlines(sol_file)
+      if isempty(lines)
+        return nothing, nothing
+      end
+
+      # First line is the number of nodes
+      # Remaining lines contain the tour (0-indexed node indices)
+      tour_nodes = Int[]
+      for line in lines[2:end]
+        for s in split(strip(line))
+          push!(tour_nodes, parse(Int, s) + 1)  # Convert to 1-indexed
+        end
+      end
+
+      # Calculate tour cost
+      if length(tour_nodes) >= n
+        cost = 0.0
+        for i in 1:n
+          from = tour_nodes[i]
+          to = tour_nodes[mod1(i + 1, n)]
+          cost += tsp.weights[from, to]
+        end
+        return cost, elapsed
+      else
+        return nothing, nothing
+      end
+
+    catch e
+      println("Concorde error: $e")
+      return nothing, nothing
+    end
+  end
+end