剑指offer（26）二叉搜索树与双向链表

/* function TreeNode(x) {
    this.val = x;
    this.left = null;
    this.right = null;
} */
function Convert(pRootOfTree)
{
    // write code here
    if(pRootOfTree == null) return null;
    let pLast=null;
    pLast=ConvertNode(pRootOfTree,pLast);
    let pHead=pLast;
    while(pHead&&pHead.left){
        pHead=pHead.left;
    }
    return pHead;
}
function ConvertNode(pNode,pLast){
    if(pNode==null) return;
    if(pNode.left){
        pLast=ConvertNode(pNode.left,pLast);
    }
    pNode.left=pLast;
    if(pLast){
        pLast.right=pNode;
    }
    pLast=pNode;
    if(pNode.right){
        pLast=ConvertNode(pNode.right,pLast);
    }
    return pLast;
}