From e2b975486234d07bd732bf290fce8cb28144a814 Mon Sep 17 00:00:00 2001
From: Piotr Idzik <65706193+vil02@users.noreply.github.com>
Date: Thu, 23 May 2024 19:45:08 +0200
Subject: [PATCH] tests: add tests of `LongestIncreasingSubsequence` (#1660)

---
 .../LongestIncreasingSubsequence.js           |  3 +++
 .../LongestIncreasingSubsequence.test.js      | 24 +++++++++++++++++++
 2 files changed, 27 insertions(+)
 create mode 100644 Dynamic-Programming/tests/LongestIncreasingSubsequence.test.js

diff --git a/Dynamic-Programming/LongestIncreasingSubsequence.js b/Dynamic-Programming/LongestIncreasingSubsequence.js
index b9319db58..b8e1847cd 100644
--- a/Dynamic-Programming/LongestIncreasingSubsequence.js
+++ b/Dynamic-Programming/LongestIncreasingSubsequence.js
@@ -6,6 +6,9 @@
 // Return the length of the Longest Increasing Subsequence, given array x
 function longestIncreasingSubsequence(x) {
   const length = x.length
+  if (length == 0) {
+    return 0
+  }
   const dp = Array(length).fill(1)
 
   let res = 1
diff --git a/Dynamic-Programming/tests/LongestIncreasingSubsequence.test.js b/Dynamic-Programming/tests/LongestIncreasingSubsequence.test.js
new file mode 100644
index 000000000..9a8024aa9
--- /dev/null
+++ b/Dynamic-Programming/tests/LongestIncreasingSubsequence.test.js
@@ -0,0 +1,24 @@
+import { longestIncreasingSubsequence } from '../LongestIncreasingSubsequence'
+
+describe('Testing longestIncreasingSubsequence', () => {
+  it.each([
+    [[], 0],
+    [[1], 1],
+    [[2, 2], 1],
+    [[3, 3, 3], 1],
+    [[4, 4, 4, 4], 1],
+    [[1, 2], 2],
+    [[1, 2, 2, 2, 2], 2],
+    [[1, 0, 2], 2],
+    [[1, 10, 2, 30], 3],
+    [[5, 8, 3, 7, 9, 1], 3],
+    [[10, 9, 2, 5, 3, 7, 101, 18], 4],
+    [[10, 10, 9, 9, 2, 2, 5, 5, 3, 3, 7, 7, 101, 101, 18, 18], 4],
+    [[0, 1, 0, 3, 2, 3], 4],
+    [[1, 1, 2, 2, 2], 2],
+    [[1, 1, 2, 2, 2, 3, 3, 3, 3], 3],
+    [[0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15], 6]
+  ])('check with %j', (input, expected) => {
+    expect(longestIncreasingSubsequence(input)).toBe(expected)
+  })
+})