剑指offer 二叉搜索树与双向链表

public TreeNode Convert(TreeNode pRootOfTree){

if(pRootOfTree == null) return null;
return rightConvert(pRootOfTree, null);

}
public TreeNode leftConvert(TreeNode pRootOfTree,TreeNode preNode) {
if(pRootOfTree == null) return null;

pRootOfTree.left = leftConvert(pRootOfTree.left,pRootOfTree);
pRootOfTree.right = rightConvert(pRootOfTree.right,pRootOfTree);

while (pRootOfTree.right != null) pRootOfTree = pRootOfTree.right;
pRootOfTree.right = preNode;
return pRootOfTree;

}

public TreeNode rightConvert(TreeNode pRootOfTree,TreeNode preNode) {
if(pRootOfTree == null) return null;

pRootOfTree.left = leftConvert(pRootOfTree.left,pRootOfTree);
pRootOfTree.right = rightConvert(pRootOfTree.right,pRootOfTree);

while (pRootOfTree.left != null) pRootOfTree = pRootOfTree.left;
pRootOfTree.left = preNode;
return pRootOfTree;

}