Build a binary tree, search nodes, and delete nodes C and C ++

The program is to create a binary sorting tree, find the node to return its parent node, return NULL when the failure, delete the node is divided into four situations: 1. Left subtree and right subtree are empty; 2. Left subtree is empty, right subtree is not empty; 3. Left subtree is not empty, right subtree is empty; 4. Left and right subtree are not empty.

C language version (implemented using struct ):

# Include <stdio. h> # include <stdlib. h> typedef int DataType; typedef struct BTree {DataType data; struct BTree * Tleft; struct BTree * Tright;} * BTree; BTree CreateTree (); // create a BTree insert (BTree root, DataType data); // insert the node void InBTree (BTree root); // traverse void PreBTree (BTree root) in the middle order ); // first traverse void PostBTree (BTree root); // then traverse BTree findPostion (BTree root, int deleteNode, int * flags ); // find the appropriate insertion point BTree delNode (B Tree root, BTree parent, int flags); // Delete the Tree node int main () {BTree root = NULL; int flags = 0; int deleteNode = 0; BTree parent = NULL; // char choiceAgain = 'y'; root = CreateTree (); printf ("\ n sequential traversal:"); InBTree (root ); printf ("\ n pre-order traversal:"); PreBTree (root); printf ("\ n post-order traversal:"); PostBTree (root ); printf ("\ n"); do {printf ("node to be deleted:"); scanf ("% d", & deleteNode); parent = findPostion (root, deleteNode, & flags); ro Ot = delNode (root, parent, flags); printf ("result after deletion:"); printf ("\ n sequential traversal:"); InBTree (root ); printf ("\ n pre-order traversal:"); PreBTree (root); printf ("\ n post-order traversal:"); PostBTree (root); choiceAgain = 'n '; printf ("\ nDelete Again (Y) or N?: "); Getchar (); scanf (" % c ", & choiceAgain);} while (choiceAgain = 'y' | choiceAgain = 'y '); printf ("\ nDone! \ N "); return 0;} BTree CreateTree () {BTree root = NULL; DataType temp = 0; printf (" enter a node, ending with 0: \ n "); scanf ("% d", & temp); while (temp! = 0) {root = insert (root, temp); scanf ("% d", & temp);} return root;} BTree insert (BTree root, DataType data) {BTree ptr = root; BTree tempNode; BTree newNode = (BTree) malloc (sizeof (struct BTree); newNode-> data = data; newNode-> Tleft = NULL; newNode-> Tright = NULL; if (ptr = NULL) {return newNode;} else {while (ptr! = NULL) {tempNode = ptr; if (ptr-> data> = data) {ptr = ptr-> Tleft;} else {ptr = ptr-> Tright ;}} if (tempNode-> data> = data) {tempNode-> Tleft = newNode;} else {tempNode-> Tright = newNode;} return root;} BTree findPostion (BTree root, int deleteNode, int * flags) {BTree parentNode = root; BTree temp = root; * flags = 0; while (temp! = NULL) {if (temp-> data = deleteNode) {return parentNode;} else {parentNode = temp; if (temp-> data> deleteNode) {temp = temp-> Tleft; * flags =-1;} else {temp = temp-> Tright; * flags = 1 ;}} return NULL ;} BTree delNode (BTree root, BTree parent, int flags) {BTree deleteNode = NULL; if (parent = NULL) {printf ("deleted node not found! \ N "); return root;} switch (flags) {case-1: deleteNode = parent-> Tleft; break; case 0: deleteNode = parent; break; case 1: deleteNode = parent-> Tright; break; default: printf ("ERROR! \ N "); exit (1);} if (deleteNode-> Tleft = NULL & deleteNode-> Tright = NULL) {if (parent-> Tleft = deleteNode) {parent-> Tleft = NULL;} else if (parent-> Tright = deleteNode) {parent-> Tright = NULL ;} else {parent = NULL;} free (deleteNode);} else if (deleteNode-> Tleft = NULL & deleteNode-> Tright! = NULL) {if (deleteNode-> data = root-> data) {root = deleteNode-> Tright ;} else {if (parent-> Tleft-> data = deleteNode-> data) {parent-> Tleft = deleteNode-> Tright ;} else {parent-> Tright = deleteNode-> Tright;} free (deleteNode);} else if (deleteNode-> Tleft! = NULL & deleteNode-> Tright = NULL) {if (deleteNode-> data = root-> data) {root = deleteNode-> Tleft ;} else {if (parent-> Tleft-> data = deleteNode-> data) {parent-> Tleft = deleteNode-> Tleft ;} else {parent-> Tright = deleteNode-> Tleft ;}} free (deleteNode);} else {BTree temp = deleteNode-> Tleft; BTree tempParent = deleteNode; while (temp-> Tright! = NULL) {tempParent = temp; temp = temp-> Tright;} deleteNode-> data = temp-> data; if (tempParent-> Tleft = temp) {tempParent-> Tleft = temp-> Tleft;} else {tempParent-> Tright = temp-> Tleft;} printf ("temp = % d \ n ", temp-> data); free (temp);} return root;} void InBTree (BTree root) {if (root! = NULL) {InBTree (root-> Tleft); printf ("% d", root-> data); InBTree (root-> Tright );}} void PreBTree (BTree root) {if (root! = NULL) {printf ("% d", root-> data); PreBTree (root-> Tleft); PreBTree (root-> Tright );}} void PostBTree (BTree root) {if (root! = NULL) {PostBTree (root-> Tleft); PostBTree (root-> Tright); printf ("% d", root-> data );}}

C ++ version (implemented by class)

# Include <iostream. h ># include <cstring> typedef int keytype; # define num 11 class binstree; Class binstreenode {public: keytype key; binstreenode * lchild; binstreenode * rchild; binstreenode () {lchild = NULL; rchild = NULL ;}; class binstree {public: binstreenode * root; binstree () {root = NULL ;}~ Binstree () {// Delete root;} binstreenode * bstreesearch (binstreenode * BT, keytype K, binstreenode * & P); void bstreeinsert (binstreenode * & BT, keytype K ); int bstreedelete (binstreenode * & BT, keytype K); void bstreepreorder (binstreenode * BT); bool isempty () {return root = NULL ;}}; /*** Binary Tree sorting search algorithm * searches for the node of element K in the binary tree with the root pointer Bt. if the search is successful, returns the pointer to this node * parameter P points to the found node; otherwise, a null pointer is returned. parameter P points to the parent node that K should insert */binstreenode * bi Nstree: bstreesearch (binstreenode * BT, keytype K, binstreenode * & P) {binstreenode * q = NULL; q = Bt; while (q) {P = Q; if (Q-> key = k) {return (p);} If (Q-> key> K) q = Q-> lchild; else q = Q-> rchild;} return NULL;}/*** insert node algorithm of the binary tree * BT points to the root node of the binary tree, insert the node of element K */void binstree: bstreeinsert (binstreenode * & BT, keytype K) {binstreenode * P = NULL, * q; q = Bt; if (bstreesearch (Q, K, P) = NULL) {Binstreenode * r = new binstreenode; r-> key = K; r-> lchild = r-> rchild = NULL; If (q = NULL) {bt = R; // The inserted node is the root node of the tree.} If (P & K <p-> key) P-> lchild = r; else if (P) p-> rchild = r ;}}/*** sequential traversal */void binstree: bstreepreorder (binstreenode * BT) {If (BT! = NULL) {cout <Bt-> key <"; bstreepreorder (BT-> lchild); bstreepreorder (BT-> rchild );}} /*** Node Deletion algorithm of the Binary Tree **: delete nodes whose elements are K in the binary tree. * BT points to the root node of the binary tree * 1 is returned after deletion, 0 is returned if no operation is successful. */INT binstree: bstreedelete (binstreenode * & BT, keytype K) {binstreenode * F, * P, * q, * s; P = Bt; F = NULL; // search for the node with the keyword K and find out the two sides of the node while (P & P-> key! = K) {f = P; If (p-> key> K) P = p-> lchild; else P = p-> rchild;} If (P = NULL) // return 0 if the node to be deleted cannot be found; If (p-> lchild = NULL) // The left subtree of the node to be deleted is null {If (F = NULL) // The node to be deleted is the root node bt = p-> rchild; else if (F-> lchild = P) // The node to be deleted is the left node of the parent node F-> lchild = p-> rchild; else F-> rchild = p-> rchild; // The node to be deleted is the right node Delete P of the parent node ;} else // The node to be deleted has the left subtree {q = P; S = p-> lchild; while (S-> rchild) // find the rightmost node {q = s; S = s-> rchild;} If (q = P) in the left subtree of the node to be deleted) q-> lchild = s-> lchild; else Q-> rchild = s-> lchild; P-> key = s-> key; Delete s;} return 1 ;} int main (void) {int A [num] = {34, 18, 76, 13, 52, 82, 16, 67, 58, 73, 72}; int I; binstree BST; binstreenode * PBT = NULL, * P = NULL, * PT = NULL; for (I = 0; I <num; I ++) {BST. bstreeinsert (PBT, a [I]); // create a binary sorting tree} Pt = BST. bstreesearch (PBT, 52, p); // search for the sort binary tree BST. bstreepreorder (PBT); cout <Endl; BST. bstreedelete (PBT, 13); // Delete BST without left children. bstreepreorder (PBT); cout <Endl; BST. bstreedelete (PBT, 76); // Delete the BST when the left child exists. bstreepreorder (PBT); cout <Endl; return 0 ;}