Question

JAVA

I got a function that sorts an array of cars (carLot) by MPG. Can someone modify so that it can sort the array of cars by MPG from lowest to highest instead.

private void selectionSort(ArrayList<Car> list) {
             for (int i = 0; i < list.size() - 1; i++) {
             // Find the minimum in the list[i..list.length-1]
             Car currentMax = list.get(i);
             int currentMaxIndex = i;

             for (int j = i + 1; j < list.size(); j++) {
                 if (currentMax.getMPG() < list.get(j).getMPG()) {
                    currentMax = list.get(j);
                    currentMaxIndex = j;
                }
            }

            // Swap list[i] with list[currentMinIndex] if necessary;
             if (currentMaxIndex != i) {
                 list.set(currentMaxIndex, list.get(i));
                 }
                 list.set(i, currentMax);
            }
        }

Answer 1

Complete java program:

import java.util.ArrayList;

public class Car

{

private int MPG;

//constructor

Car(int MPG)

{

this.MPG=MPG;

}

public Car()

{

}

//getter and setter methods

public int getMPG()

{

return MPG;

}

public void setMPG(int mPG)

{

MPG = mPG;

}

private void selectionSort(ArrayList<Car> list)

{

for (int i = 0; i < list.size() - 1; i++)

{

// Find the minimum in the list[i..list.length-1]

Car currentMax = list.get(i);

int currentMaxIndex = i;

for (int j = i + 1; j < list.size(); j++)

{

//just make here greater than(>) symbol

if (currentMax.getMPG() > list.get(j).getMPG())

{

currentMax = list.get(j);

currentMaxIndex = j;

}

}

// Swap list[i] with list[currentMinIndex] if necessary;

if (currentMaxIndex != i)

{

list.set(currentMaxIndex, list.get(i));

}

list.set(i, currentMax);

}

//loop to print the MPG from lowest to highest instead.

for(int i=0;i<list.size();i++)

System.out.println(list.get(i).MPG);

}

//driver method to test the car

public static void main(String[] args)

{

//creating arrayList of Cars

ArrayList<Car> carsList= new ArrayList<Car>();

//adding Cars objects to list

carsList.add(new Car(120));

carsList.add(new Car(180));

carsList.add(new Car(150));

carsList.add(new Car(110));

carsList.add(new Car(160));

//calling the method

Car obj = new Car();

obj.selectionSort(carsList);

}

}

Output:

110
120
150
160
180