Class Problems

Lecture 24 - Arraylist/src/Problems.java:4–47

import java.util.Collections;

public class Problems {
    static void reverseList(ArrayList<Integer> list){
        int i = 0, j = list.size() - 1;

        while(i < j){
            /*
                int temp = a;
                a = b;
                b = temp;
             */
            Integer temp = Integer.valueOf(list.get(i));
            list.set(i, list.get(j));
            list.set(j, temp);
            i++;
            j--;
        }
    }

    public static void main(String[] args) {
        ArrayList<Integer> list = new ArrayList<>();
        list.add(0);
        list.add(10);
        list.add(3);
        list.add(5);
        list.add(22);
        list.add(10);
        System.out.println("Original List " + list);
        Collections.reverse(list);
        System.out.println("Reversed List " + list);
        Collections.sort(list);
        System.out.println("Ascending order " + list);
        Collections.sort(list, Collections.reverseOrder());
        System.out.println("Desc order " + list);

        ArrayList<String> l1 = new ArrayList<>();
        l1.add("Welcome");
        l1.add("To");
        l1.add("Physics");
        l1.add("Wallah");
        System.out.println("OG " + l1);
        Collections.sort(l1, Collections.reverseOrder());
        System.out.println("Sorted " + l1);
    }
}