[LEET-3392] add 3392

Author: fishercoder1534

paginated_contents/algorithms/4th_thousand/README.md

@@ -1,6 +1,7 @@
 | #    | Title                                                                                                                                                               | Solutions                                                                                                                         | Video                                                                         | Difficulty | Tag                                                                  
 |------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------|------------|----------------------------------------------------------------------
 | 3396 | [Minimum Number of Operations to Make Elements in Array Distinct](https://leetcode.com/problems/minimum-number-of-operations-to-make-elements-in-array-distinct/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3396.java) |                                                                               | Easy       |
+| 3392 | [Count Subarrays of Length Three With a Condition](https://leetcode.com/problems/count-subarrays-of-length-three-with-a-condition/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3392.java) |                                                                               | Easy       |
 | 3370 | [Smallest Number With All Set Bits](https://leetcode.com/problems/smallest-number-with-all-set-bits/)                                                               | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3370.java) |                                                                               | Easy       |
 | 3364 | [Minimum Positive Sum Subarray](https://leetcode.com/problems/minimum-positive-sum-subarray/)                                                                       | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3364.java) |                                                                               | Easy       |
 | 3360 | [Stone Removal Game](https://leetcode.com/problems/stone-removal-game/)                                                                                             | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3360.java) |                                                                               | Easy       |

src/main/java/com/fishercoder/solutions/fourththousand/_3392.java

@@ -0,0 +1,15 @@
+package com.fishercoder.solutions.fourththousand;
+
+public class _3392 {
+    public static class Solution1 {
+        public int countSubarrays(int[] nums) {
+            int count = 0;
+            for (int i = 0; i < nums.length - 2; i++) {
+                if ((nums[i] + nums[i + 2]) * 2 == nums[i + 1]) {
+                    count++;
+                }
+            }
+            return count;
+        }
+    }
+}