//Evaluate the question tree to get the answer
public double evaluate()
{
// Debug.Log ("Evaluation: " + value + " " + type);
switch (type)
{
case Type.Null:
return(value);
case Type.Add:
return(left.evaluate() + right.evaluate());
case Type.Sub:
return(left.evaluate() - right.evaluate());
case Type.Mul:
return(left.evaluate() * right.evaluate());
case Type.Div:
Assert.IsTrue(right.evaluate() != 0.0d);
return(left.evaluate() / right.evaluate());
}
return(double.NaN);
}
public static Question generate()
{
List <RandNode> opdNodes = new List <RandNode> ();
List <RandNode> oprNodes = new List <RandNode> ();
string questionStr = "";
RandNode rn = getOpd(GlobalSettings.largestNum);
opdNodes.Add(rn);
questionStr += rn.number.ToString();
for (int i = 0; i < GlobalSettings.numberOfOperators - 1; i++)
{
RandNode opr = getOps();
/** Deal with divide, we only want integer for dividen **/
RandNode opd;
if (opr.type == QTree.Type.Div)
{
opd = getValidDivisor(getPrevDiv(oprNodes, opdNodes, opdNodes.Count - 1));
}
else
{
opd = getOpd(GlobalSettings.largestNum);
}
//Add them in
opdNodes.Add(opd);
oprNodes.Add(opr);
questionStr += " " + QTree.getOperatorStr(opr.type) + " " + opd.number.ToString();
}
//Debug.Log (questionStr);
QTree root = QTreeBuilder.build(opdNodes, oprNodes);
int rightAnswer = (int)root.evaluate();
int score = getScore(root);
string explaination = getExplaination(root);
Debug.Log("Explaination " + explaination + ", " + score);
Question question = new Question(questionStr, rightAnswer, score, explaination);
//Debug.Log ("The correct answer is " + question.answer.ToString ());
return(question);
}