import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;

import java.util.Arrays;
import java.util.List;

public class SimpleTest {
    private static Subsequencer subsequencer;

    @BeforeClass
    public static void init() {
        subsequencer = new DynamicSubsequencer();
    }

    @Test
    public void test1() {
        List<Integer> sequence = Arrays.asList(5, 2, 8, 6, 3, 6, 9, 7);
        check(sequence, subsequencer.findSubsequence(sequence), 4);
    }

    @Test
    public void test2() {
        List<Integer> sequence = Arrays.asList(7, 7, 1, 5);
        check(sequence, subsequencer.findSubsequence(sequence), 2);
    }

    @Test
    public void test3() {
        List<Integer> sequence = Arrays.asList(6, 10, 4, 9, 3, 5);
        check(sequence, subsequencer.findSubsequence(sequence), 2);
    }

    @Test
    public void test4() {
        List<Integer> sequence = Arrays.asList(3, 2, 10, 5, 9, 10, 3);
        check(sequence, subsequencer.findSubsequence(sequence), 4);
    }

    @Test
    public void test5() {
        List<Integer> sequence = Arrays.asList(5, 2, 2, 6, 8, 9, 2, 6);
        check(sequence, subsequencer.findSubsequence(sequence), 4);
    }

    @Test
    public void test6() {
        List<Integer> sequence = Arrays.asList(7, 6, 10, 4, 9, 8, 8, 9, 5);
        check(sequence, subsequencer.findSubsequence(sequence), 3);
    }

    @Test
    public void test7() {
        List<Integer> sequence = Arrays.asList(1, 9, 1, 2, 7, 11, 11, 1, 10, 8);
        check(sequence, subsequencer.findSubsequence(sequence), 4);
    }

    @Test
    public void test8() {
        List<Integer> sequence = Arrays.asList(6, 4, 6, 2, 4, 10, 4, 4, 3, 9, 8);
        check(sequence, subsequencer.findSubsequence(sequence), 3);
    }

    static void check(List<Integer> sequence, List<Integer> subsequence, int length) {
        Assert.assertEquals("Subsequence does not have the correct length.", length, subsequence.size());
        for (int i = 1; i < length; i++) {
            int previous = subsequence.get(i - 1);
            int index = subsequence.get(i);
            Assert.assertTrue("Indices are not increasing.", index > previous);
            Assert.assertTrue("Subsequence is not increasing.", sequence.get(index) > sequence.get(previous));
        }
    }
}