//
// Supporting material for lecture 11
// - helper methods
// - validating time, again :)

// read in two times and then do soemthing with them!!!
//
import FormatIO.*;

public class Demo11a {

 public static void main(String[] args){
	Console con    = new Console();
	int firstTime  = -999,
	    secondTime = -999;
	while (!validTime(firstTime)){
	    con.print("Enter first time: ");
	    firstTime = con.readInt();
	}
	while (!validTime(secondTime)){
	    con.print("Enter second time: ");
	    secondTime = con.readInt();
	}
	con.println("Diff: " + (firstTime - secondTime)); // (9)
 }
    
    private static boolean validTime(int x){
	return x > 0 && x/100 < 24 && x%100 < 60;
    }
}
//
// Same as Demo11, all that we have done is declare method validTime after we have used it
// I prefer Demo11 to Demo11a
//
// How would we measure the difference between two
// times in 24 hour format? 
//