Command Line Calculator in Objective C [closed] - objective-c

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I want to implement a command line application in C/Objective C which will act as a calculator of more than two numbers.
E.g ./calc 5 + 4 * 6
= 29
I just need an idea or simple algorithm to start. I will appreciate any help on this.

Answer 1

The algorithm you want is the infix notation to postfix notation converter.
You can find some more info on it over here.
http://scriptasylum.com/tutorials/infix_postfix/algorithms/infix-postfix/index.htm.
EDIT: I am not sure if this will help, but here is an implementation in Java. I'm not familiar with Objective-C
// converts a infix string to postfix string
private void convertInfixToPostfix(){
// create an empty operand stack
operatorStack = new Stack<>();
Operator operator = null;
Operand operand = null;
for(int i = 0; i < expressionTokens.size(); i++){
String token = expressionTokens.get(i);
Element element = new Element(token);
if(element.isOperand(token)){ // check if element is operand
// add the element to the postfix string
operand = new Operand(element.getStringValue());
postFixString.add(operand);
}
else if(operatorStack.isEmpty()){
// push the token to the operator stack, its an operator
operator = new Operator(element.getStringValue());
operatorStack.push(operator);
}
else {
operator = new Operator(element.getStringValue());
while(!operatorStack.isEmpty() &&
(operatorStack.peek().getPrecedence()
<= operator.getPrecedence()))
postFixString.add(operatorStack.pop());
operatorStack.push(operator);
}
}
// add the rest of the operator stack to the postfix string
while(!operatorStack.isEmpty()){
Operator remainingOperator = operatorStack.pop();
postFixString.add(remainingOperator);
}
}