干货8：二叉树

#ifndef __BTREE_H__#define __BTREE_H__#define BLEFT  0    // 表示插入二叉树的左边#define BRIGHT 1    // 表示插入二叉树的右边#define TRUE   1#define FALSE  0typedef char BTreeData;// 二叉树的结点typedef struct _btreeNode{BTreeData data;struct _btreeNode *lchild;   // 指向左孩子结点的指针struct _btreeNode *rchild;   // 指向右孩子结点的指针}BTreeNode;// 二叉树typedef struct _btree{BTreeNode *root;     // 指向二叉树的根节点int  count;          // 记录二叉树结点的个数}BTree;typedef void (*Print_BTree)(BTreeNode*);// 创建一棵二叉树BTree *Create_BTree();// pos 走的路径 值类似 110（左右右）  011 （右右左）// count  代表走的步数// flag   代表被替换的结点应该插入在新节点的位置，如果是BLEFT 表示插在左边，BRIGHT表示插在右边int Btree_Insert(BTree *tree, BTreeData data, int pos, int count, int flag);void Display (BTree* tree, Print_BTree pfunc);int Delete (BTree *tree, int pos, int count);int BTree_Height (BTree *);int BTree_Degree (BTree *);int BTree_Clear (BTree *);int BTree_Destroy (BTree **);// 前序遍历void pre_order (BTreeNode *node);void mid_order (BTreeNode *node);void last_order (BTreeNode *node);#endif // __BTREE_H__

#include "BTree.h"#include <stdlib.h>#include <stdio.h>BTree *Create_BTree(){BTree *btree = (BTree*)malloc(sizeof(BTree)/sizeof(char));if (btree == NULL)return NULL;btree->count = 0;btree->root  = NULL;return btree;}int Btree_Insert(BTree *tree, BTreeData data, int pos, int count, int flag){if (tree == NULL || (flag != BLEFT && flag != BRIGHT))return FALSE;BTreeNode *node = (BTreeNode*)malloc(sizeof(BTreeNode)/sizeof(char));if (node == NULL)return FALSE;node->data = data;node->lchild = NULL;node->rchild = NULL;// 找插入的位置BTreeNode *parent = NULL;BTreeNode *current = tree->root; // current 一开始指向根节点，根节点的父节点是空int way;   // 保存当前走的位置while (count > 0 && current != NULL){way = pos & 1;    // 取出当前走的方向pos = pos >> 1;   // 移去走过的路线// 因为当前位置就是走完以后的位置的父节点parent = current;if (way == BLEFT)   // 往左走current = current->lchild;elsecurrent = current->rchild;count--;}// 把被替换掉的结点插入到新节点下面if (flag == BLEFT)node->lchild = current;elsenode->rchild = current;// 把新节点插入到二叉树中,way保存了应该插入在父节点的左边还是右边if (parent != NULL){if (way == BLEFT)parent->lchild = node;elseparent->rchild = node;}else{tree->root = node;  // 替换根节点}tree->count ++;return TRUE;}void r_display(BTreeNode* node, Print_BTree pfunc,int gap){int i;if (node == NULL){for (i = 0; i < gap; i++){printf ("-");}printf ("\n");return;}for (i = 0; i < gap; i++){printf ("-");}// 打印结点// printf ("%c\n", node->data);pfunc (node);if (node->lchild != NULL || node->rchild != NULL){// 打印左孩子r_display (node->lchild, pfunc, gap+4);// 打印右孩子r_display (node->rchild, pfunc, gap+4);}}void Display (BTree* tree, Print_BTree pfunc){if (tree == NULL)return;r_display(tree->root, pfunc, 0);}void r_delete (BTree *tree, BTreeNode* node){if (node == NULL || tree == NULL)return ;// 先删除左孩子r_delete (tree, node->lchild);// 删除右孩子r_delete (tree, node->rchild);free (node);tree->count --;}int Delete (BTree *tree, int pos, int count){if (tree == NULL)return FALSE;// 找结点BTreeNode* parent  = NULL;BTreeNode* current = tree->root;int way;while (count > 0 && current != NULL){way = pos & 1;pos = pos >> 1;parent = current;if (way == BLEFT)current = current->lchild;elsecurrent = current->rchild;count --;}if (parent != NULL){if (way == BLEFT)parent->lchild = NULL;elseparent->rchild = NULL;}else{tree->root = NULL;}// 释放结点r_delete (tree, current);return TRUE;}int r_height (BTreeNode *node){if (node == NULL)return 0;int lh = r_height (node->lchild);int rh = r_height (node->rchild);return (lh > rh ? lh+1 : rh+1);}int BTree_Height (BTree *tree){if (tree == NULL)return FALSE;int ret = r_height(tree->root);return ret;}int r_degree (BTreeNode * node){if (node == NULL)return 0;int degree = 0;if (node->lchild != NULL)degree++;if (node->rchild != NULL)degree++;if (degree == 1){int ld = r_degree (node->lchild);if (ld == 2)return 2;int rd = r_degree (node->rchild);if (rd == 2)return 2;}return degree;}int BTree_Degree (BTree *tree){if (tree == NULL)return FALSE;int ret = r_degree(tree->root);return ret;}int BTree_Clear (BTree *tree){if (tree == NULL)return FALSE;Delete (tree, 0, 0);  // 删除根节点tree->root = NULL;return TRUE;}int BTree_Destroy (BTree **tree){if (tree == NULL)return FALSE;BTree_Clear(*tree);free (*tree);*tree = NULL;return TRUE;}void pre_order (BTreeNode *node){if (node == NULL)return;printf ("%4c", node->data);pre_order (node->lchild);pre_order (node->rchild);}void mid_order (BTreeNode *node){if (node == NULL)return;mid_order (node->lchild);printf ("%4c", node->data);mid_order (node->rchild);}void last_order (BTreeNode *node){if (node == NULL)return;last_order (node->lchild);last_order (node->rchild);printf ("%4c", node->data);}