From 550a49b794af9a354a8b3d72e5424294ec4481f0 Mon Sep 17 00:00:00 2001
From: Stackingrule <38368554+Stackingrule@users.noreply.github.com>
Date: Mon, 21 Dec 2020 15:54:57 +0800
Subject: [PATCH] feat:add Solution.cpp for 0109.Convert Sorted List to Binary
 Search Tree

---
 .../Solution.cpp                              | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 solution/0100-0199/0109.Convert Sorted List to Binary Search Tree/Solution.cpp

diff --git a/solution/0100-0199/0109.Convert Sorted List to Binary Search Tree/Solution.cpp b/solution/0100-0199/0109.Convert Sorted List to Binary Search Tree/Solution.cpp
new file mode 100644
index 0000000000000..96671a35a8875
--- /dev/null
+++ b/solution/0100-0199/0109.Convert Sorted List to Binary Search Tree/Solution.cpp	
@@ -0,0 +1,19 @@
+class Solution {
+public:
+    TreeNode* sortedListToBST(ListNode* head) {
+        if (!head) return nullptr;
+        if (!head->next) return new TreeNode(head->val);
+        ListNode *fast = head, *slow = head, *last = slow;
+        while (fast->next && fast->next->next) {
+            last = slow;
+            slow = slow->next;
+            fast = fast->next->next;
+        }
+        fast = slow->next;
+        last->next = nullptr;
+        TreeNode *cur = new TreeNode(slow->val);
+        if (head != slow) cur->left = sortedListToBST(head);
+        cur->right = sortedListToBST(fast);
+        return cur; 
+    }
+};
\ No newline at end of file