Hi! I wanted to make a java calculator. However, I\'m a bit confused. in the if
ID: 3588059 • Letter: H
Question
Hi!
I wanted to make a java calculator. However, I'm a bit confused. in the
if (name.equals("+")) {
// TODO: your code here
return toDoubleHelper(variables, node.getChildren().get(0)) + toDoubleHelper(variables, node.getChildren().get(1));
This should be okay since we want to add the two childrenNodes after the "+" operator node. Can somebody please help me? Below is the related methods.
/**
* Takes the given AstNode node and attempts to convert it into a double.
*
* Returns a number AstNode containing the computed double.
*
* @throws EvaluationError if any of the expressions contains an undefined variable.
* @throws EvaluationError if any of the expressions uses an unknown operation.
*/
public static AstNode toDouble(Environment env, AstNode node) {
// To help you get started, we've implemented this method for you.
// You should fill in the TODOs in the 'toDoubleHelper' method.
return new AstNode(toDoubleHelper(env.getVariables(), node));
}
private static double toDoubleHelper(IDictionary<String, AstNode> variables, AstNode node) {
// There are three types of nodes, so we have three cases.
if (node.isNumber()) {
// TODO: your code here
return node.getNumericValue();
} else if (node.isVariable()) {
if (!variables.containsKey(node.getName())) {
// If the expression contains an undefined variable, we give up.
throw new EvaluationError("Undefined variable: " + node.getName());
}
// TODO: your code here
return (variables.get(node.getName())).getNumericValue();
} else {
String name = node.getName();
// TODO: your code here
if (name.equals("+")) {
// TODO: your code here
return toDoubleHelper(variables, node.getChildren().get(0)) + toDoubleHelper(variables, node.getChildren().get(1));
} else if (name.equals("-")) {
// TODO: your code here
throw new NotYetImplementedException();
} else if (name.equals("*")) {
// TODO: your code here
throw new NotYetImplementedException();
} else if (name.equals("/")) {
// TODO: your code here
throw new NotYetImplementedException();
} else if (name.equals("^")) {
// TODO: your code here
throw new NotYetImplementedException();
} else if (name.equals("negate")) {
// TODO: your code here
throw new NotYetImplementedException();
} else if (name.equals("sin")) {
// TODO: your code here
throw new NotYetImplementedException();
} else if (name.equals("cos")) {
// TODO: your code here
throw new NotYetImplementedException();
} else {
throw new EvaluationError("Unknown operation: " + name);
}
}
}
public static AstNode simplify(Environment env, AstNode node) {
// Try writing this one on your own!
// Hint 1: Your code will likely be structured roughly similarly
// to your "toDouble" method
// Hint 2: When you're implementing constant folding, you may want
// to call your "toDouble" method in some way
// TODO: Your code here
return new AstNode(simplifyHelper(env.getVariables(), node));
}
private static double simplifyHelper(IDictionary<String, AstNode> variables, AstNode node) {
// There are three types of nodes, so we have three cases.
if (node.isNumber()) {
// TODO: your code here
return node.getNumericValue();
} else if (node.isVariable()) {
if (!variables.containsKey(node.getName())) {
// If the expression contains an undefined variable, we give up.
throw new EvaluationError("Undefined variable: " + node.getName());
}
// TODO: your code here
return (variables.get(node.getName())).getNumericValue();
} else {
String name = node.getName();
// TODO: your code here
if (name.equals("+")) {
// TODO: your code here
return simplifyHelper(variables, node.getChildren().get(0)) + simplifyHelper(variables, node.getChildren().get(1));
} else if (name.equals("-")) {
// TODO: your code here
throw new NotYetImplementedException();
} else if (name.equals("*")) {
// TODO: your code here
throw new NotYetImplementedException();
} else if (name.equals("/")) {
// TODO: your code here
throw new NotYetImplementedException();
} else if (name.equals("^")) {
// TODO: your code here
throw new NotYetImplementedException();
} else if (name.equals("negate")) {
// TODO: your code here
throw new NotYetImplementedException();
} else if (name.equals("sin")) {
// TODO: your code here
throw new NotYetImplementedException();
} else if (name.equals("cos")) {
// TODO: your code here
throw new NotYetImplementedException();
} else {
throw new EvaluationError("Unknown operation: " + name);
}
}
}
T-Mobile LTE 9:21 AM 100% 13 +2 7 2 17 4 >>> x + y >>> x := 1 10 >>xy 11 1 +y 12 13 | >>> y := 2 14 2 15 16>>> xy 17 3 The users type input into the lines that start with . The line that follows immediately after is the output This example demonstrates the two core features we can perform using this calculator: evaluate math expressions (line 1) and symbolically work with variables (lines 7 17) When we first typedin x y , we were unable to evaluate or simplify the expressions because the variables x and y are currently unknownExplanation / Answer
struct LinkedNode
{
Type info;
LinkedNode *next;
};
template
class LinkedList
{
public:
LinkedList();
LinkedList(const LinkedList& other);
~LinkedList();
LinkedList& operator=(const LinkedList& other);
int insert(const Type&);
Type* find(int) const;
Type* get(int) const;
int remove(int);
void clear();
int size() const;
void print() const;
};
template
LinkedList::LinkedList()
{
}
template
LinkedList::LinkedList(const LinkedList& other)
{
}
template
LinkedList::~LinkedList()
{
}
template
LinkedList& LinkedList::operator=(const LinkedList& other)
{
return
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