Swap.java

package arraylist;

import java.util.ArrayList;

public class Swap {
    public static void swap(ArrayList<Integer> list, int index1, int index2) {
        int temp = list.get(index1);
        list.set(index1, list.get(index2));
        list.set(index2, temp);

    }

    public static void main(String[] args) {
        ArrayList<Integer> list = new ArrayList<>();

        list.add(2);
        list.add(5);
        list.add(9);
        list.add(3);
        list.add(6);

        int index1 = 1;
        int index2 = 3;

        System.out.println("Org list: " + list);
        swap(list, index1, index2);
        System.out.println("Swapped list: " + list);
    }
}
// TC: O(1)

// Swap two numbers
// list = 2, 5, 9, 3, 6
// index 1 = 1, index 2 = 3