有序链表转换二叉搜索树

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
/**
 * Definition for a binary tree node.
 * type TreeNode struct {
 *     Val int
 *     Left *TreeNode
 *     Right *TreeNode
 * }
 */
func sortedListToBST(head *ListNode) *TreeNode {
    var nodes []ListNode
    for head !=nil {
       nodes= append(nodes,*head) 
       head = head.Next
    }
    return builder(nodes,0,len(nodes)-1)
}
func builder(nodes []ListNode,left,right int)*TreeNode{
    if left >right {
        return nil
    }
    mid :=(left+right+1)/2
    root :=&TreeNode{nodes[mid].Val,nil,nil}
    root.Left = builder(nodes,left,mid-1)
    root.Right = builder(nodes,mid+1,right)
    return root
}