Merge pull request doocs#318 from Stackingrule/dev

feat:add Solution.cpp for 0108.Convert Sorted Array to Binary Search …

Author: Stackingrule

Diff for: solution/0100-0199/0108.Convert Sorted Array to Binary Search Tree/Solution.cpp

@@ -0,0 +1,25 @@
+/**
+ * Definition for a binary tree node.
+ * struct TreeNode {
+ *     int val;
+ *     TreeNode *left;
+ *     TreeNode *right;
+ *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
+ * };
+ */
+class Solution {
+public:
+    TreeNode* sortedArrayToBST(vector<int>& nums) {
+        return helper(nums, 0, nums.size() - 1);
+    }
+
+private:
+    TreeNode* helper(vector<int> &nums, int left, int right) {
+        if (left > right) return nullptr;
+        int mid = left + (right - left) / 2;
+        TreeNode *cur = new TreeNode(nums[mid]);
+        cur->left = helper(nums, left, mid - 1);
+        cur->right = helper(nums, mid + 1, right);
+        return cur;
+    }
+};