109. Convert Sorted List to Binary Search Tree (java)

Author: bluesword12350

solution/0109.Convert Sorted List to Binary Search Tree/Solution.java

@@ -0,0 +1,19 @@
+class Solution {
+    public TreeNode sortedListToBST(ListNode head) {
+        if(head==null) return null;
+        if(head.next==null) return new TreeNode(head.val);
+        ListNode slow = head;
+        ListNode fast = head;
+        ListNode prev = null;
+        while(fast!=null && fast.next!=null){
+            prev = slow;
+            slow=slow.next;
+            fast=fast.next.next;
+        }
+        TreeNode root = new TreeNode(Objects.requireNonNull(prev).next.val);
+        prev.next = null;
+        root.left = sortedListToBST(head);
+        root.right = sortedListToBST(slow.next);
+        return root;
+    }
+}