From 0834268753a293a4cf6f15db370b13dee538450a Mon Sep 17 00:00:00 2001
From: Vincent Jacques <vincent@vincent-jacques.net>
Date: Mon, 16 Oct 2023 12:53:49 +0000
Subject: [PATCH] Fix alternative names with '--max-imbalance'

---
 lincs/liblincs/generation.cpp | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/lincs/liblincs/generation.cpp b/lincs/liblincs/generation.cpp
index 6b4b2075..2bb9b4fb 100644
--- a/lincs/liblincs/generation.cpp
+++ b/lincs/liblincs/generation.cpp
@@ -203,11 +203,7 @@ Alternatives generate_uniform_classified_alternatives(
       criteria_values[criterion_index] = values_distributions[criterion_index](gen);
     }
 
-    alternatives.push_back(Alternative{
-      "Alternative " + std::to_string(alt_index + 1),
-      criteria_values,
-      std::nullopt,
-    });
+    alternatives.push_back(Alternative{"", criteria_values, std::nullopt});
   }
 
   Alternatives alts{problem, alternatives};
@@ -295,8 +291,6 @@ Alternatives generate_balanced_classified_alternatives(
   while (min_size > 0) {
     ++iterations_with_no_effect;
 
-    // @todo(Bug, soon) Fix naming of generated alternatives:
-    // index starts at zero in each call to 'generate_uniform_classified_alternatives' so names are duplicated
     Alternatives candidates = generate_uniform_classified_alternatives(problem, model, multiplier * alternatives_count, gen);
 
     for (const auto& candidate : candidates.alternatives) {
@@ -364,11 +358,15 @@ Alternatives generate_classified_alternatives(
 
   std::mt19937 gen(random_seed);
 
-  if (max_imbalance) {
-    return generate_balanced_classified_alternatives(problem, model, alternatives_count, *max_imbalance, gen);
-  } else {
-    return generate_uniform_classified_alternatives(problem, model, alternatives_count, gen);
+  Alternatives alternatives = max_imbalance ?
+    generate_balanced_classified_alternatives(problem, model, alternatives_count, *max_imbalance, gen) :
+    generate_uniform_classified_alternatives(problem, model, alternatives_count, gen);
+
+  for (unsigned alternative_index = 0; alternative_index != alternatives_count; ++alternative_index) {
+    alternatives.alternatives[alternative_index].name = "Alternative " + std::to_string(alternative_index + 1);
   }
+
+  return alternatives;
 }
 
 void check_histogram(const Problem& problem, const Model& model, const std::optional<float> max_imbalance, const unsigned a, const unsigned b) {
@@ -395,6 +393,14 @@ TEST_CASE("Generate balanced classified alternatives") {
   check_histogram(problem, model, 0.0, 50, 50);
 }
 
+TEST_CASE("Generate balanced classified alternatives - names are correct") {
+  Problem problem = generate_classification_problem(3, 2, 42);
+  Model model = generate_mrsort_classification_model(problem, 42, 2);
+  Alternatives alternatives = generate_classified_alternatives(problem, model, 100, 42, 0.);
+
+  CHECK(alternatives.alternatives[99].name == "Alternative 100");
+}
+
 TEST_CASE("Generate balanced classified alternatives - many seeds") {
   // Assert that we can generate a balanced learning set for all generated models