From f70716426c8377b50f36aa39bf23580aeb75afd4 Mon Sep 17 00:00:00 2001
From: Jinguo Liu <cacate0129@gmail.com>
Date: Sat, 14 Dec 2024 01:39:22 +0800
Subject: [PATCH] new implement findmax and findmin interfaces (#90)

---
 Project.toml                 |  2 +-
 src/GenericTensorNetworks.jl |  3 +++
 src/interfaces.jl            | 15 +++++++++++++++
 test/interfaces.jl           | 12 ++++++++++--
 4 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/Project.toml b/Project.toml
index 09dd63d..69bb2f3 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "GenericTensorNetworks"
 uuid = "3521c873-ad32-4bb4-b63d-f4f178f42b49"
 authors = ["GiggleLiu <cacate0129@gmail.com> and contributors"]
-version = "3.0.0"
+version = "3.1.0"
 
 [deps]
 AbstractTrees = "1520ce14-60c1-5f80-bbc7-55ef81b5835c"
diff --git a/src/GenericTensorNetworks.jl b/src/GenericTensorNetworks.jl
index 36a94c1..325b1d0 100644
--- a/src/GenericTensorNetworks.jl
+++ b/src/GenericTensorNetworks.jl
@@ -67,6 +67,9 @@ export SetCovering, is_set_covering
 # Interfaces
 export solve, SizeMax, SizeMin, PartitionFunction, CountingAll, CountingMax, CountingMin, GraphPolynomial, SingleConfigMax, SingleConfigMin, ConfigsAll, ConfigsMax, ConfigsMin, Single, AllConfigs
 
+# ProblemReductions API
+export GTNSolver
+
 # Utilities
 export save_configs, load_configs, hamming_distribution, save_sumproduct, load_sumproduct
 
diff --git a/src/interfaces.jl b/src/interfaces.jl
index 5e9e7aa..7d2e3a8 100644
--- a/src/interfaces.jl
+++ b/src/interfaces.jl
@@ -483,3 +483,18 @@ for GP in [:IndependentSet, :MaxCut, :DominatingSet, :Satisfiability, :Coloring,
 end
 size_all_negative(::SpinGlass) = false
 size_all_positive(::SpinGlass) = false
+
+# NOTE: `findmin` and `findmax` are required by `ProblemReductions.jl`
+Base.@kwdef struct GTNSolver
+    optimizer::OMEinsum.CodeOptimizer = TreeSA()
+    usecuda::Bool = false
+    T::Type = Float64
+end
+function Base.findmin(problem::AbstractProblem, solver::GTNSolver)
+    res = collect(solve(GenericTensorNetwork(problem; optimizer=solver.optimizer), ConfigsMin(; tree_storage=true); usecuda=solver.usecuda, T=solver.T)[].c)
+    return map(x -> ProblemReductions.id_to_config(problem, Int.(x) .+ 1), res)
+end
+function Base.findmax(problem::AbstractProblem, solver::GTNSolver)
+    res = collect(solve(GenericTensorNetwork(problem; optimizer=solver.optimizer), ConfigsMax(; tree_storage=true); usecuda=solver.usecuda, T=solver.T)[].c)
+    return map(x -> ProblemReductions.id_to_config(problem, Int.(x) .+ 1), res)
+end
\ No newline at end of file
diff --git a/test/interfaces.jl b/test/interfaces.jl
index 5d0dbc9..d79bd1f 100644
--- a/test/interfaces.jl
+++ b/test/interfaces.jl
@@ -1,4 +1,4 @@
-using GenericTensorNetworks
+using GenericTensorNetworks, GenericTensorNetworks.ProblemReductions
 using Graphs, Test, Random
 
 @testset "independent set problem" begin
@@ -245,4 +245,12 @@ end
     @test_throws ArgumentError solve(gp, ConfigsMin(2))
     @test solve(gp, ConfigsMin(Single)) isa Array
     @test_throws AssertionError ConfigsMin(0)
-end
\ No newline at end of file
+end
+
+@testset "GTNSolver" begin
+    sg = SpinGlass(smallgraph(:petersen), rand(15), rand(10))
+    solver1 = GTNSolver(; optimizer=TreeSA(ntrials=1))
+    solver2 = BruteForce()
+    @test Set(findmin(sg, solver1)) == Set(findmin(sg, solver2))
+    @test Set(findmax(sg, solver1)) == Set(findmax(sg, solver2))
+end