Implement llongest_increasing_subsequence function

solution21.py

@@ -1,2 +1,13 @@
 def llongest_increasing_subsequence(arr: list) -> list:
-    pass
+    if not arr:
+        return []
+    dp = [[x] for x in arr]
+    for i in range(len(arr)):
+        for j in range(i):
+            if arr[j] < arr[i] and len(dp[j]) + 1 > len(dp[i]):
+                dp[i] = dp[j] + [arr[i]]
+    return max(dp, key = len)
+
+    print(dp)
+if __name__ == "__main__":
+    print(f"llongest_increasing_subsequence([10, 9, 2, 5, 3, 7, 101, 18] -> {llongest_increasing_subsequence([10, 9, 2, 5, 3, 7, 101, 18])}")