feat(leetcode): add No.108

Author: mickey0524

108.Convert-Sorted-Array-to-Binary-Search-Tree.go

@@ -0,0 +1,37 @@
+// https://leetcode.com/problems/convert-sorted-array-to-binary-search-tree/
+//
+// algorithms
+// Easy (52.52%)
+// Total Accepted:    294,117
+// Total Submissions: 560,015
+
+package leetcode
+
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+func sortedArrayToBST(nums []int) *TreeNode {
+	length := len(nums)
+	if length == 0 {
+		return nil
+	}
+	if length == 1 {
+		return &TreeNode{
+			Val: nums[0],
+		}
+	}
+
+	middle := length / 2
+	node := &TreeNode{
+		Val: nums[middle],
+	}
+	node.Left = sortedArrayToBST(nums[:middle])
+	node.Right = sortedArrayToBST(nums[middle+1:])
+
+	return node
+}