Add VRP test case

test/cases/vrp.jl

@@ -0,0 +1,35 @@
+using LinearAlgebra
+
+function vrp_simple()
+  A = Float64[
+      1 0 0 1 1 1 0 1 1 1 1
+      0 1 0 1 0 1 1 0 1 1 1
+      0 0 1 0 1 0 1 1 1 1 1
+  ]
+  b = Float64[1, 1, 1]
+  c = Float64[2, 4, 4, 4, 4, 4, 5, 4, 5, 6, 5];
+
+  ϵ = 1
+  ρ = sum(abs, c) + ϵ
+  Q = diagm(c) + ρ * (A'A - 2 * diagm(A'b))
+  β = ρ * b'b
+
+  return Q, β
+end
+
+@testset "Vehicle Routing Problem (VRP)" begin
+  # See https://secquoia.github.io/QUBOBook/QUBO%20and%20Ising%20Models.html
+  Q, beta = vrp_simple()
+
+  E, psi = solve(Q, nothing, beta)
+  x = TenSolver.sample(psi)
+
+  # Known Solution
+  @test E ≈ 5.0 atol=1e-4
+
+  @test [0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0] in psi
+  @test [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1] in psi
+  @test x in ( [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]
+             , [0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0]
+             )
+end

test/runtests.jl

@@ -24,3 +24,6 @@ end
 include(filepath("qubo.jl"))
 # JuMP interface
 include(filepath("jump.jl"))
+
+# Cases from papers
+include(filepath("cases/vrp.jl"))