#!/usr/bin/env python
# coding: utf-8

# This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges).

# # Challenge Notebook

# ## Problem: Find the longest increasing subsequence.
# 
# * [Constraints](#Constraints)
# * [Test Cases](#Test-Cases)
# * [Algorithm](#Algorithm)
# * [Code](#Code)
# * [Unit Test](#Unit-Test)
# * [Solution Notebook](#Solution-Notebook)

# ## Constraints
# 
# * Are duplicates possible?
#     * Yes
# * Can we assume the inputs are integers?
#     * Yes
# * Can we assume the inputs are valid?
#     * No
# * Do we expect the result to be an array of the longest increasing subsequence?
#     * Yes
# * Can we assume this fits memory?
#     * Yes

# ## Test Cases
# 
# * None -> Exception
# * [] -> []
# * [3, 4, -1, 0, 6, 2, 3] -> [-1, 0, 2, 3]

# ## Algorithm
# 
# Refer to the [Solution Notebook]().  If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start.

# ## Code

# In[ ]:


class Subsequence(object):

    def longest_inc_subseq(self, seq):
        # TODO: Implement me
        pass


# ## Unit Test

# **The following unit test is expected to fail until you solve the challenge.**

# In[ ]:


# %load test_longest_increasing_subseq.py
import unittest


class TestLongestIncreasingSubseq(unittest.TestCase):

    def test_longest_increasing_subseq(self):
        subseq = Subsequence()
        self.assertRaises(TypeError, subseq.longest_inc_subseq, None)
        self.assertEqual(subseq.longest_inc_subseq([]), [])
        seq = [3, 4, -1, 0, 6, 2, 3]
        expected = [-1, 0, 2, 3]
        self.assertEqual(subseq.longest_inc_subseq(seq), expected)
        print('Success: test_longest_increasing_subseq')


def main():
    test = TestLongestIncreasingSubseq()
    test.test_longest_increasing_subseq()


if __name__ == '__main__':
    main()


# ## Solution Notebook
# 
# Review the [Solution Notebook]() for a discussion on algorithms and code solutions.