Question

Java, no imports:

Given a list of integers, round each number to the nearest multiple of 5.
       2.5-7.49 round to 5. 7.5-12.49 round to 10. 12.5-17.49 round to 15. etc.
       return the sum of all the rounded elements.
       Implement this way for credit:
       Fill in the method directly below this one called helperRound() to round each number.

Call that method and use the sum of the returned values.

       helperSum({4.3, 16.7}) returns 20
       helperSum({25.7, 21.2, 27.5}) returns 75
       helperSum({2.5}) returns 5
       helperSum({2.49, 12.49, 40.2, 42.5}) returns 95
       @param nums is an arrayList of doubles
       @return the sum of the all elements after rounding
   */
public static int helperSum(ArrayList<Double> nums)
{
       int sum = 0;
       return sum;
}//end helperSum

   /**
        Method HelperRound will round a number up or down to the nearest 5.

        @param num double number,
        @return the rounded up or down number to the nearest multiple of 5.
    */
public static int helperRound(double n){
           int rounded = 0;

           return rounded;
}//end HelperRound

Answer 1

Program Code Screenshot

Sample Output

Program Code to Copy

import java.util.ArrayList;
import java.util.Arrays;

class Main{
    public static int helperSum(ArrayList<Double> nums)
    {
        int sum = 0;
        //Loop through all elements in the array
        for(double x : nums){
            //Find sum of helperRounds
            sum += helperRound(x);
        }
        return sum;
    }//end helperSum

    /**
     Method HelperRound will round a number up or down to the nearest 5.

     @param n double number,
     @return the rounded up or down number to the nearest multiple of 5.
     */
    public static int helperRound(double n){
        //l5 and r5 are the nearest multiples of 5 on either side
        int l5 = (int)n;
        while(l5%5!=0){
            l5--;
        }
        int r5 = (int)n;
        //Check the closest l5, or r5
        while(r5%5!=0){
            r5++;
        }
        if(n-l5<r5-n){
            return l5;
        }
        return r5;
    }//end HelperRound

    public static void main(String[] args) {
        double d[] = {4.3,16.7};
        ArrayList<Double> list = new ArrayList<>();
        for(double x : d){
            list.add(x);
        }
        System.out.println(Arrays.toString(d)+" : "+helperSum(list));
        d = new double[]{25.7, 21.2, 27.5};
        list = new ArrayList<>();
        for(double x : d){
            list.add(x);
        }
        System.out.println(Arrays.toString(d)+" : "+helperSum(list));
        d = new double[]{2.5};
        list = new ArrayList<>();
        for(double x : d){
            list.add(x);
        }
        System.out.println(Arrays.toString(d)+" : "+helperSum(list));
        d = new double[]{2.49, 12.49, 40.2, 42.5};
        list = new ArrayList<>();
        for(double x : d){
            list.add(x);
        }
        System.out.println(Arrays.toString(d)+" : "+helperSum(list));
    }
}