Create 1968-array-with-elements-not-equal-to-average-of-neighbors.kt

Author: a93a

kotlin/1968-array-with-elements-not-equal-to-average-of-neighbors.kt

@@ -0,0 +1,37 @@
+/*
+* O(nlogn) solution (similar to wiggle sort)
+*/
+class Solution {
+    fun rearrangeArray(nums: IntArray): IntArray {
+        nums.sort()
+
+        val res = IntArray(nums.size)
+        var i = 0
+        var left = 0
+        var right = nums.lastIndex
+
+        while (i < res.size) {
+            res[i++] = nums[left++]
+            if (left <= right)
+                res[i++] = nums[right--]
+        }
+
+        return res
+    }
+}
+
+/*
+* O(n) solution, check for any increasing/decreasing subarrays at i - i to i + 1, if found i with i + 1 to remove the increasing/decreasing subarray
+*/
+class Solution {
+    fun rearrangeArray(nums: IntArray): IntArray {
+
+        for (i in 1 until nums.lastIndex) {
+            if (nums[i - 1] < nums[i] && nums[i] < nums[i + 1] || 
+                nums[i - 1] > nums[i] && nums[i] > nums[i + 1])
+                nums[i] = nums[i + 1].also { nums[i + 1] = nums[i] }
+        }
+
+        return nums
+    }
+}