Question

Please show public static void main (String args[]) {} method too!

9. Given a list containing two or more integers, this method returns a set containing the two integers in the list that are closest to each other; i.e. the absolute value of the difference between them is minimal. The returned set must be sorted. public static Set<Integer> closest(List<Integers list) Example, if list = [21, 4, 2, 12, 18, 24, 16, 7, 20, 39, -3, 26] then the return should be [20, 21]

Answer 1

import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

public class ListClosest {

    public static Set<Integer> closest(List<Integer> list) {
        Set<Integer> set = new HashSet<>();
        int minDistance = Integer.MAX_VALUE, d;
        for (int i = 0; i < list.size(); i++) {
            for (int j = i+1; j < list.size(); j++) {
                d = Math.abs(list.get(i) - list.get(j));
                if (d < minDistance) {
                    minDistance = d;
                    set.clear();
                    set.add(list.get(i));
                    set.add(list.get(j));
                }
            }
        }
        return set;
    }

    public static void main(String[] args) {
        System.out.println(closest(Arrays.asList(21, 4, 2, 12, 18, 24, 16, 7, 20, 39, -3, 26)));
    }
}

[20, 21] Process finished with exit code 0