普通二叉树转换成搜索二叉树

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

struct ListNode {     int data;     ListNode *lchild,*rchild; };   void CreateBSTree(ListNode *B2_root,ListNode *BSTree_root) {      if(BSTree_root==NULL)      {          BSTree_root = (ListNode*)malloc(sizeof(ListNode));          BSTree_root->lchild=BSTree_root->rchild=NULL;          BSTree_root->data=B2_root->data;          return ;      }      if(B2_root->data<BSTree_root->data) CreateBSTree(B2_root,BSTree_root->lchild);      if(B2_root->data>BSTree_root->data) CreateBSTree(B2_root,BSTree_root->rchild); }   void PreOrder(ListNode *B2_root,ListNode *BSTree_root) {      if(B2_root==NULL) return ;//根节点就为空      CreateBSTree(B2_root,BSTree_root);      if(B2_root->lchild!=NULL) PreOrder(B2_root->lchild,BSTree_root);      if(B2_root->rchild!=NULL) PreOrder(B2_root->rchild,BSTree_root); }   ListNode* CreateBSTree(ListNode* B2_root) {     ListNode* BSTree_root=NULL;     PreOrder(B2_root,BSTree_root);     return BSTree_root; }