Thread: Need help creating this program

Hello ixjaybeexi.

This can be a starting block for you:

import java.util.Scanner;
 
public class StudentAttendance {
 
    /**
     * JavaProgrammingForums.com
     */    
    static int lectures, points;
 
    // attendance method
    public static void attendance(){
 
 
    }
 
    public static void main(String[] args) {
 
        Scanner sc = new Scanner(System.in);
        System.out.println("How many lectures has this student been to?");
        lectures = sc.nextInt();
        attendance();
 
    }
 
}

Write your algorithm out for if he attends n lectures. If it's always going to be 7 lectures, you might as well do this:

System.out.println("For 7 lectures you get 12 points");

Even if you're test case is 7, they probably want it to work for any arbitrary n.

what is the algorithm for n lectures attended?

first 5 give 2 points, all rest give 1?

pseudo-code:

count = lecturesAttended
while count > 0
     if count > 5
          increase points by 1
     else
          increase points by 2
     decrease count
end

what do you know how to do? From the way you phrased the question, it seems like you really do need some way to test conditionals, and if/else are the simplest.

if/else is basically like it sounds like:

if it's sunny, go play outside.
else, play video games.

if/else statements are really simple. You ask is something true? If it is, you execute one set of code. If it's not, you execute the else code. It's almost exactly like the language equivalent: if something, else something different.

if (conditional)
{
    do something;
}
else
{
     do something else;
}

here's what an if/else statement looks like in code. The conditional is the thing you want to test, and if it evaluates to true, do what ever is surrounded by the first {}'s. If it's false, do what ever is surrounded by the second {}'s.

Mmm, there's a few problems but they can be easily fixed.

You don't want to add 1 or 2 to the lecturesAttended to get the points, but rather multiply. You also have it backwards. It should be 2 points/lecture for the first 5 and 1 point after. Also, you still need to add the 5 points for the first 5 lectures, and then (I think you can work out why, if not please ask)

an if/else statement only does one or the other... not both. Also, you want to add the 5 points if the lectures is greater than 5.

Yes, you can do points = points+points, but it's not helpful here.

if lectures <= 5
points = 2 * lectures
else
points = 5 + lectures

it's because of variable scope. I don't know a good way to explain it, but basically you're declaring the int inside the if statement, so nothing outside of it can see it.

The last problem I see is that you forgot to put parenthesis around the conditions for the if statement.

public static int attendance(int lecturesAttended)
{
     int points;
     if (lecturesAttended <= 5)
     {
          points = 2*lecturesAttended;
     }
     else
     {
          points = 5 + lecturesAttended;
     }
     return points;
}

here's a full 1 i came up with while reading that ,idk about grammar spelling or syntax but otherwise here it is

 
public int attendance (int a){
    if (a >= 5){  // checks if the times he attended is 5 or more 
      points = 10;   // if it is he gets the 10 points for each of the 1st 5 lectures
      a = a - 5;          // then while subtract 5 from the times he attended
       while (a > 0) {    // and for every time after that he gets 1 more point 
          points = points + 1;   // adds the point
          a = a - 1;  // subtracts 1 from the attendant before the loop runs again 
       }                  // so that he wouldn't get free points  
   } else {
       while (a > 0) {   // if he hasn't attended the first 5 lectures then he gains 2 points for each he has 
          points = points + 2;
          a = a - 1;     // essentially the same as the previous over 5 point loop but gives 2 points instead 
       }   
   return points;
}

look about right?

Yep, that's right. There's only one bit of syntax error. You forgot to declare and initialize points to 0.

In terms of performance, my solution is better ( O(1) vs. O(n) )

after i posted and read back through it i realized , i was just too lazy to fix it XP

i expanded mine so its more understandable
and added it in a class with main for testing

i think it was 2 points for each of the first 5 ( aka 1a = 2p , or 2a = 4p)
then if its over 5 they get 1 more for each ( aka 6a = 11p , or 9a = 14p)
( a = attendance , p = points )

public class Attendance {
 
	public static void main(String[] args) {
 
		int response = attendance(4);
 
		System.out
				.println("some 1 attended four times , witch means his score should be 8. it is "
						+ response);
 
		response = attendance(5);
 
		System.out
				.println("some 1 attended five times , witch means his score should be 10. it is "
						+ response);
 
		response = attendance(6);
 
		System.out
				.println("some 1 attended six times , witch means his score should be 11. it is "
						+ response);
 
		System.out
				.println("this should test all three run troughs of the method ");
	}
 
	public static int attendance(int attend) {
 
		int points = 0;
 
		if (attend >= 5) {                                  // checks if the times he attended is 5 or more
 
			points = 10;                                   // if it is he gets the 10 points for each of the 1st 5
							                       // lectures
 
			attend = attend - 5;                      // then while subtract 5 from the times he
									       // attended
 
			while (attend > 0) {                       // and for every time after that he gets 1 more
									       // point
 
				points = points + 1;               // adds the point
 
				attend = attend - 1;               // subtracts 1 from the attendant before
										// the loop runs again
			}                                                      // so that he wouldn't get free points
 
		} else {
 
			while (attend > 0) {                // if he hasn't attended the first 5 lectures
									// then he gains 2 points for each he has
 
				points = points + 2;
 
				attend = attend - 1;               // essentially the same as the previous
										// over 5 point loop but gives 2 points
										// instead
 
			}
 
		}
		return points;
	}
}