Unique Values

Lab Java Beginner 10 points

Read n integers. Print how many distinct values there are, then the distinct values in the order they first appeared (use a LinkedHashSet).

Input

n, then n integers.

Output

Two lines.

Example

Input

7
3 1 3 2 1 5 3

Output

4
3 1 2 5

Sample input available Sample output available

Editor

Java

Hints

A Set ignores duplicates.

LinkedHashSet remembers insertion order.

Solution explanation

HashSet = fast, no order; LinkedHashSet = insertion order; TreeSet = sorted order.

Show solution

import java.util.LinkedHashSet;
import java.util.Scanner;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        Set<Integer> seen = new LinkedHashSet<Integer>();
        for (int i = 0; i < n; i++) {
            seen.add(sc.nextInt());
        }
        System.out.println(seen.size());
        StringBuilder sb = new StringBuilder();
        for (int x : seen) {
            sb.append(sb.length() > 0 ? " " : "").append(x);
        }
        System.out.println(sb);
    }
}

Output

Answer