Fix some mistakes to correct tests

lib/Files/ArffFiles.h

@@ -0,0 +1,34 @@
+#ifndef ARFFFILES_H
+#define ARFFFILES_H
+
+#include <string>
+#include <vector>
+
+using namespace std;
+
+class ArffFiles {
+private:
+    vector<string> lines;
+    vector<pair<string, string>> attributes;
+    string className;
+    string classType;
+    vector<vector<float>> X;
+    vector<int> y;
+
+    void generateDataset(bool);
+
+public:
+    ArffFiles();
+    void load(const string&, bool = true);
+    vector<string> getLines() const;
+    unsigned long int getSize() const;
+    string getClassName() const;
+    string getClassType() const;
+    static string trim(const string&);
+    vector<vector<float>>& getX();
+    vector<int>& getY();
+    vector<pair<string, string>> getAttributes() const;
+    static vector<int> factorize(const vector<string>& labels_t);
+};
+
+#endif