//**********
//SimpleCalculator.java
//John Purcell 
//CS 160: HW5
//October 22, 2008
//This program reads user input and returns the operation while checking
//for "user error" to make sure inputs are within parameters
//**********


import java.util.Scanner;
public class SimpleCalculator {
	
	public static void main (String[] args){
		System.out.println("Type and equation");
		System.out.println("Example: 3 * 4 (include spaces)");
		Scanner S = new Scanner(System.in);
		double a=0;
		double b=0;
		double r=0;
		double var=.000001;
		//though the case may be handled if the variables are not assigned, by initializing them before
		//any other assignment, the program will compile without error.
		if (S.hasNextDouble()){;
			a = S.nextDouble();
		}
		else{
			System.out.println("operand needs to be a number");
			System.exit(1);
		}
		String O = S.next();
		//the string variable just needs to be assigned.  By doing the order <number> <string> <number> 
		//the proper inputs are received.
		
		if (S.hasNextDouble()){
			b = S.nextDouble();
		}
		else{
			System.out.println("operand needs to be a number");
			System.exit(1);
			//Both (a) and (b) are checked by the hasNextDouble() checker.  By using the widest
			//checker, they only need to be passed once.  The INT or DOUBLE check is done later.	
		}
		if (O.equals("+")){
			r=(a-(int)a)-(b-(int)b);
			//the (r) equation checks whether the variables are both INT.  If r != 0 (in this case (var) 
			//to make sure small numbers are handled as well) then the program will pass the numbers as double.
			if (r<var){
			System.out.println("Answer: "+(int)(a+b));
			}
			else{
				System.out.println("Answer: "+(double)(a+b));
				//though (double) may be redundant, it makes the program easier to read as to what is being
				//passed.
			}
		}
		else if (O.equals("-")){
			r=(a-(int)a)-(b-(int)b);
			if (r<var){
			System.out.println("Answer: "+(int)(a-b));
			}
			else{
				System.out.println("Answer: "+(double)(a-b));
			}
		}
		else if (O.equals("*")){
			r=(a-(int)a)-(b-(int)b);
			if (r<var){
				System.out.println("Answer: "+(int)(a*b));
			}
			else{
				System.out.println("Answer: "+(double)(a*b));
			}
		}
		else if (O.equals("/")){
			r=(a-(int)a)-(b-(int)b);
			if (r<var){
				System.out.println("Answer: "+(int)(a/b));
			}
			else{
				System.out.println("Answer: "+(double)(a/b));
			}
		}
		else if (O.equals("%")){
			r=(a-(int)a)-(b-(int)b);
			if (r<var){
				System.out.println("Answer: "+(int)(a%b));
			}
			else{
				System.out.println("Answer: "+(double)(a%b));
			}
		}
		else{
			System.out.println("illegal operator");
		}
}
}