Binary lookup tree transforms into a sorted doubly linked list

Enter a two-dollar lookup tree to convert the two-dollar lookup tree into a sorted doubly linked list. Requires that no new nodes be created, only the pointer is adjusted.

One of the most intuitive ideas is to find the smallest number in the binary search tree and add it to the linked list.

</pre><pre name= "code" class= "CPP" >//BST2list.cpp: Defines the entry point of the console application. #include "stdafx.h" #include <iostream> using namespace std; #define INFINITY 1000000struct binode{int ele; binode* Lnode; Binode* Rnode;}; int min; Binode*head, *tail; Binode*minnode; Binode*p; Binode*create_tree () {Binode * root = new Binode; Binode*node1 = new Binode; Binode*node2 = new Binode; Binode*node3 = new Binode; Binode*node4 = new Binode; BINODE*NODE5 = new Binode; Binode*node6 = new Binode; Binode*node7 = new Binode; Binode*node8 = new Binode; Binode*node9 = new Binode; Binode*node10 = new Binode; Binode*node11 = new Binode;root->ele = 45;node1->ele = 38;node2->ele = 55;node3->ele = 33;node4->ele = 43;n Ode5->ele = 19;node6->ele = 16;node7->ele = 52;node8->ele = 58;node9->ele = 50;node10->ele = 41;node11-& Gt;ele = 35;root->lnode = Node1;root->rnode = Node2;node1->lnode = Node3;node1->rnode = node4;node2-> Lnode = Node7;node2->rnode = Node8;node3->lnode = noDe5;node3->rnode = Node11;node4->lnode = Node10;node4->rnode = Null;node5->lnode = Node6;node5->rnode = Null;node6->lnode = Null;node6->rnode = Null;node7->lnode = Node9;node7->rnode = NULL;node8->lnode = NULL ; node8->rnode = Null;node9->lnode = Null;node9->rnode = Null;node10->lnode = NULL;node10->rnode = NULL;  Node11->lnode = Null;node11->rnode = Null;//binode*node12 = new Binode;  Node12->ele = 12;  Node12->lnode = NULL;  Node12->rnode = NULL;  Node6->lnode = Node11; return root;} Binode*find_min (Binode*node) {//minnode=node; this sentence causes a recursive error if (node = = NULL) return null;if (Node->ele < min) {min = node->ele;minnode = node;} if (node->lnode! = NULL) {if (Node->lnode->ele < min) {min = Node->lnode->ele;minnode = Node->lnode;} Find_min (Node->lnode);} if (node->rnode! = NULL) {if (Node->rnode->ele < min) {min = Node->rnode->ele;minnode = Node->rnode;} Find_min (Node->rnode);} Return Minnode;}  void Findparent (Binode*node, binode*parent) {if (parent = = NULL) return;if (Parent->lnode = = Node | | parent->rnode = = node) p = parent;findparent (node, parent->lnode); findparent (node, parent->rnode);} Binode*bst2list (binode*root) {min = Infinity;minnode = NULL; Binode*n = Find_min (root); while (n) {if (n = = root) {if (N->rnode! = NULL) root = N->rnode;else{tail->rnode = N;N-&G T;lnode = Tail;tail = N;return head;}} ElseIf (N->rnode! = null) {p = Null;findparent (n, root); if (P! = null) P->lnode = N->rnode;n->rnode = null;} Else{p = Null;findparent (n, root); if (P! = null) P->lnode = NULL;} if (head = = Null&&tail = = NULL) {head = tail = n;} else if (head = = tail) {Tail->rnode = N;n->lnode = Tail;tail = N;head->rnode = tail;} Else{tail->rnode = N;n->lnode = Tail;tail = n;} Min = Infinity;minnode = Null;n = Find_min (root);}} int _tmain (int argc, _tchar* argv[]) {head = tail = NULL; Binode*root = Create_tree (); head = bst2list (root); system ("pause");return 0;} 

Find_min recursive Minnode The position of the data is incorrect, resulting in the start of recursive failure. So pay special attention to the processing of variables that affect the recursive process.

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Binary lookup tree transforms into a sorted doubly linked list