Second Highest Salary with Streams (and the Nth Highest)

import java.util.*;
import java.util.stream.*;

public class SecondHighest {
    public static void main(String[] args) {
        List<Integer> salaries = List.of(50000, 90000, 70000, 90000, 65000);

        System.out.println(nthHighest(salaries, 1));              // 90000
        System.out.println(nthHighest(salaries, 2));              // 70000
        System.out.println(nthHighest(salaries, 3));              // 65000
        System.out.println(nthHighest(salaries, 9));              // -1
        System.out.println(nthHighest(List.of(10), 2));           // -1
        System.out.println(secondHighestLoop(salaries));          // 70000
    }

    // distinct() makes the two 90000 values count once. O(n log n) because of the sort.
    static int nthHighest(List<Integer> values, int n) {
        return values.stream()
                .distinct()
                .sorted(Comparator.reverseOrder())
                .skip(n - 1)
                .findFirst()
                .orElse(-1);                                       // -1 when there are fewer than n distinct values
    }

    // The same answer in one pass with O(1) extra space, without streams.
    static int secondHighestLoop(List<Integer> values) {
        int first = Integer.MIN_VALUE, second = Integer.MIN_VALUE;
        for (int v : values) {
            if (v > first) {
                second = first;
                first = v;
            } else if (v > second && v != first) {
                second = v;
            }
        }
        return second == Integer.MIN_VALUE ? -1 : second;
    }
}