题解 | #二叉搜索树与双向链表#

public class TreeNode {
    int val = 0;
    TreeNode left = null;
    TreeNode right = null;

    public TreeNode(int val) {
        this.val = val;

    }

}
*/
public class Solution {
    TreeNode head = null;
    TreeNode pre = null;
    public TreeNode Convert(TreeNode pRootOfTree) {
       dfs(pRootOfTree); 
        return head;
    }
    public void dfs(TreeNode cur){
        if(cur == null){
            return;
        }
        dfs(cur.left);
        if(head != null){
            pre.right = cur;
        }else{
            head = cur;
        }
        cur.left = pre;
        pre = cur;
        dfs(cur.right);
    }
}