some refactoring

file.cs

@@ -0,0 +1,81 @@
+class file
+{
+    public Tuple<List<zConstraints>,List<Constraints>> readFile()
+    {
+        List<zConstraints> zConstraintsList = new List<zConstraints>();
+        List<Constraints> constraintsList = new List<Constraints>();
+        //read file "input.txt" line by line 
+        string line;
+        StreamReader file = new StreamReader("input.txt");
+        while ((line = file.ReadLine()) != null)
+        {
+            // if line contains "min" or "max"
+            if (line.Contains("min") || line.Contains("max"))
+            {
+                zConstraints constraints = new zConstraints();
+                if (line.Contains("min"))
+                {
+                    constraints.minMax = "min";
+                }
+                else
+                {
+                    constraints.minMax = "max";
+                }
+                // remove "min" or "max" from line
+                line = line.Remove(0, line.IndexOf(constraints.minMax) + constraints.minMax.Length);
+                // split line by " "
+                string[] lineArray = line.Split(' ');
+                //remove empty elements from array
+                lineArray = lineArray.Where(x => !string.IsNullOrEmpty(x)).ToArray();
+
+                // add variables to constraints.variables after parsing them to float
+                List<float> variables = new List<float>();
+                foreach (string variable in lineArray)
+                {
+                    variables.Add(float.Parse(variable));
+                    
+                }
+                constraints.values = variables;
+                // add constraints to list
+                zConstraintsList.Add(constraints);
+            }
+            else
+            {
+                // split line by " "
+                string[] lineArray = line.Split(' ');
+                //remove empty elements from array
+                lineArray = lineArray.Where(x => !string.IsNullOrEmpty(x)).ToArray();
+                // for each element in array
+                Constraints constraints = new Constraints();
+                List<float> variables = new List<float>();
+                foreach (string variable in lineArray)
+                {
+                    if (variable.Contains("=") || variable.Contains(">") || variable.Contains("<"))
+                    {
+                        constraints.sign = variable;
+                    }
+                    else
+                    {
+                        variables.Add(float.Parse(variable));
+                    }
+                }
+                constraints.values = variables;
+                constraintsList.Add(constraints);
+            }
+        }
+        file.Close();
+        return new Tuple<List<zConstraints>, List<Constraints>>(zConstraintsList, constraintsList);
+    }
+}
+class zConstraints
+{
+    public string minMax;
+    public List<float> values; 
+}   
+
+class Constraints
+{
+    public List<float> values;
+
+    public string sign;
+}