solves #3105: Longest Strictly Increasing or Strictly Decreasing Subarray in java

Author: anishLearnsToCode

Diff for: README.md

@@ -902,7 +902,7 @@
 | 3090 | [Maximum Length Substring With Two Occurrences](https://leetcode.com/problems/maximum-length-substring-with-two-occurrences)                                           |                                                                          [![Java](assets/java.png)](src/MaximumLengthSubstringWithTwoOccurrences.java)                                                                           |                                                                                                                                   |
 | 3095 | [Shortest Subarray With OR at Least K I](https://leetcode.com/problems/shortest-subarray-with-or-at-least-k-i)                                                         |                                                                               [![Java](assets/java.png)](src/ShortestSubarrayWithORAtLeastKI.java)                                                                               |                                                                                                                                   |
 | 3099 | [Harshad Number](https://leetcode.com/problems/harshad-number)                                                                                                         |                                                                                        [![Java](assets/java.png)](src/HarshadNumber.java)                                                                                        |                                                                                                                                   |
-| 3105 | [Longest Strictly Increasing or Strictly Decreasing Subarray](https://leetcode.com/problems/longest-strictly-increasing-or-strictly-decreasing-subarray)               |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 3105 | [Longest Strictly Increasing or Strictly Decreasing Subarray](https://leetcode.com/problems/longest-strictly-increasing-or-strictly-decreasing-subarray)               |                                                                    [![Java](assets/java.png)](src/LongestStrictlyIncreasingOrStrictlyDecreasingSubarray.java)                                                                    |                                                                                                                                   |
 | 3110 | [Score of a String](https://leetcode.com/problems/score-of-a-string)                                                                                                   |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 3114 | [Latest Time You Can Obtain After Replacing Characters](https://leetcode.com/problems/latest-time-you-can-obtain-after-replacing-characters)                           |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 3120 | [Count the Number of Special Characters I](https://leetcode.com/problems/count-the-number-of-special-characters-i)                                                     |                                                                                                                                                                                                                                  |                                                                                                                                   |

Diff for: src/LongestStrictlyIncreasingOrStrictlyDecreasingSubarray.java

@@ -0,0 +1,38 @@
+// https://leetcode.com/problems/longest-strictly-increasing-or-strictly-decreasing-subarray
+// T: O(N)
+// S: O(1)
+
+public class LongestStrictlyIncreasingOrStrictlyDecreasingSubarray {
+    public int longestMonotonicSubarray(int[] array) {
+        return Math.max(
+            lengthLongestIncreasingSubarray(array),
+            lengthLongestDecreasingSubarray(array)
+        );
+    }
+
+    private static int lengthLongestIncreasingSubarray(int[] array) {
+        int length = 1;
+        for (int i = 1, current = 1 ; i < array.length ; i++) {
+            if (array[i] > array[i - 1]) {
+                current++;
+            } else {
+                current = 1;
+            }
+            length = Math.max(length, current);
+        }
+        return length;
+    }
+
+    private static int lengthLongestDecreasingSubarray(int[] array) {
+        int length = 1;
+        for (int i = 1, current = 1 ; i < array.length ; i++) {
+            if (array[i] < array[i - 1]) {
+                current++;
+            } else {
+                current = 1;
+            }
+            length = Math.max(length, current);
+        }
+        return length;
+    }
+}