From f72f0bfc26b59d6e1445a45517b89b3a8753000c Mon Sep 17 00:00:00 2001
From: Henri Lefebvre <hri.lefebvre@gmail.com>
Date: Wed, 18 Sep 2024 13:02:24 +0200
Subject: [PATCH] start example on PADM

---
 examples/bilevel-optimization/CMakeLists.txt  |  6 +--
 .../bilevel-optimization/padm.example.cpp     | 47 +++++++++++++++++++
 2 files changed, 49 insertions(+), 4 deletions(-)
 create mode 100644 examples/bilevel-optimization/padm.example.cpp

diff --git a/examples/bilevel-optimization/CMakeLists.txt b/examples/bilevel-optimization/CMakeLists.txt
index d7646890..aba4162c 100644
--- a/examples/bilevel-optimization/CMakeLists.txt
+++ b/examples/bilevel-optimization/CMakeLists.txt
@@ -1,5 +1,3 @@
-
 add_example(mibs)
-
-add_executable(example_kkt kkt.example.cpp)
-target_link_libraries(example_kkt PRIVATE idol)
\ No newline at end of file
+add_example(kkt)
+add_example(padm)
\ No newline at end of file
diff --git a/examples/bilevel-optimization/padm.example.cpp b/examples/bilevel-optimization/padm.example.cpp
new file mode 100644
index 00000000..2e917e2c
--- /dev/null
+++ b/examples/bilevel-optimization/padm.example.cpp
@@ -0,0 +1,47 @@
+//
+// Created by henri on 18.09.24.
+//
+#include <iostream>
+#include <idol/modeling.h>
+#include <idol/modeling/bilevel-optimization/LowerLevelDescription.h>
+#include <idol/modeling/models/KKT.h>
+#include <idol/optimizers/mixed-integer-optimization/wrappers/Gurobi/Gurobi.h>
+
+int main(int t_argc, const char** t_argv) {
+
+
+    using namespace idol;
+
+    Env env;
+    Model model(env);
+    const auto x = model.add_var(0, Inf, Continuous, "x");
+    const auto y = model.add_var(0, Inf, Continuous, "y");
+    const auto delta = model.add_var(-Inf, Inf, Continuous, "delta");
+
+    model.set_obj_expr(delta * delta);
+
+    auto c = model.add_ctr(x + delta * x + y <= 1);
+    model.add_ctr(y == 1);
+
+    Bilevel::LowerLevelDescription description(env);
+    description.make_follower_var(x);
+    description.make_follower_var(y);
+    description.make_follower_ctr(c);
+    description.set_follower_obj_expr(-2 * x - y);
+
+    Model single_level(env);
+    Reformulators::KKT(model, description).add_strong_duality_reformulation(single_level);
+
+    std::cout << model << std::endl;
+    std::cout << single_level << std::endl;
+
+    Annotation<Ctr> sub_problem(env, "sub_problem");
+
+    single_level.use(Gurobi());
+
+    single_level.optimize();
+
+    std::cout << save_primal(single_level) << std::endl;
+
+    return 0;
+}
\ No newline at end of file