Time: 2 ms (80%), Space: 45.6 MB (14.51%) - LeetHub

0941-valid-mountain-array/0941-valid-mountain-array.java

@@ -0,0 +1,12 @@
+class Solution {
+    public boolean validMountainArray(int[] arr) {
+        if (arr.length < 3) return false;
+        int left = 0;
+        int right = arr.length - 1;
+
+        while (left < arr.length - 2 && arr[left] < arr[left + 1]) left++;
+        while (right > 0 && arr[right] < arr[right - 1]) right--;
+
+        return left == right && left != 0 && right != arr.length - 1;
+    }
+}