Add comment in Statistics

src/best/Statistics.cpp

@@ -91,7 +91,7 @@ namespace platform {
     }
     void Statistics::computeWTL()
     {
-        // Compute the WTL matrix
+        // Compute the WTL matrix (Win Tie Loss)
         for (int i = 0; i < nModels; ++i) {
             wtl[i] = { 0, 0, 0 };
         }

src/main/RocAuc.cpp

@@ -48,6 +48,7 @@ namespace platform {
         double tp = 0, fp = 0;
         double totalPos = std::count(y_test.begin(), y_test.end(), classIdx);
         double totalNeg = nSamples - totalPos;
+        if (totalPos == 0 || totalNeg == 0) return 0.5; // neutral AUC
 
         for (const auto& [score, label] : scoresAndLabels) {
             if (label == 1) {