二叉搜索树BST
2015-12-27 22:46
696 查看
在二叉搜索树b中查找x的过程为:
1.若b是空树,则搜索失败,否则:
2.若x等于b的根结点的数据域之值,则查找成功;否则
3.若x小于b的根结点的数据域之值,则搜索左子树:否则
4.查找右子树
// 指针parent指向pRoot的父节点,其初始调用值为NULL
// 若查找成功,指针pTarget指向目标节点,函数返回true
// 否则指针pTarget指向查找路径上访问的最后一个节点,函数返回false
// pTarget初始值为NULL,由于函数调用过程中需要修改其指针值,所以参数传递双层指针
bool searchBST(BinaryTreeNode* pRoot, int key, BinaryTreeNode* parent, BinaryTreeNode** pTarget)
{
if(pRoot == NULL)
{
*pTarget = parent;
return false;
}
if(pRoot->value == key)
{
*pTarget = pRoot;
return true;
}
else if(pRoot->value > key)
return searchBST(pRoot->left, key, pRoot, pTarget);
else
return searchBST(pRoot->right, key, pRoot, pTarget);
}
向一个二叉搜索树b中插入一个节点s的算法,过程为:
1.若b是空树,则将s所指节点作为根节点插入,否则:
2.若s->value等于b的根节点的数据域之值,则返回,否则:
3.若s->value小于b的根节点的数据域之值,则把s所指节点插入到左子树中,否则:
4.把s所指节点插入到右子树中。(新插入节点总是叶子节点)
// 当树为空时,需要修改根结点指针值,所以参数传递双层指针
bool insertBST(BinaryTreeNode** pRoot, int key)
{
if(*pRoot == NULL)
{
BinaryTreeNode* s = new BinaryTreeNode;
s->value = key;
s->left = s->right = NULL;
*pRoot = s;
return true;
}
else if((*pRoot)->value == key)
return false;
if((*pRoot)->value > key)
return insertBST(&(*pRoot)->left, key);
else
return insertBST(&(*pRoot)->right, key);
}
在二叉查找树中删去一个节点,分三种情况讨论:
1.若*p节点为叶子节点,即PL(左子树)和PR(右子树)均为空树。由于删去叶子节点不破坏整棵树的结构,则只需修改其双亲节点的指针即可。
2.若*p节点只有左子树PL或右子树PR,此时只要另PL或PR直接成为其双亲节点*f的左子树(当*p是左子树)或右子树(当*p是右子树)即可。
3.若*p节点的左子树和右子树均不空。在删去*p之后,为保持其它元素之间的相对位置不变,可按中序遍历保持有序进行调整,可以有两种做法:其一是另*p的直接前驱(inorder predecessor)或直接后继(inorder successor)替代*p,然后再从二叉查找树中删去它的直接前驱(或直接后继)
bool deleteNode(BinaryTreeNode** pRoot)
{
BinaryTreeNode* q, *s;
if((*pRoot)->left == NULL && (*pRoot)->right == NULL)
{
delete *pRoot;
*pRoot = NULL;
}
else if((*pRoot)->right == NULL)
{
q = (*pRoot)->left;
(*pRoot)->value = q->value;
(*pRoot)->left = q->left;
(*pRoot)->right = q->right;
delete q;
}
else if((*pRoot)->left == NULL)
{
q = (*pRoot)->right;
(*pRoot)->value = q->value;
(*pRoot)->left = q->left;
(*pRoot)->right = q->right;
delete q;
}
else
{
q = *pRoot;
s = (*pRoot)->left;
while(s->right)
{
q = s;
s = s->right;
}
(*pRoot)->value = s->value;
if(q != *pRoot)
q->right = s->left;
else
q->left = s->left;
delete s;
}
return true;
}
bool deleteBST(BinaryTreeNode** pRoot, int key)
{
if(*pRoot == NULL)
return false;
if((*pRoot)->value == key)
return deleteNode(pRoot);
else if((*pRoot)->value > key)
return deleteBST(&(*pRoot)->left, key);
else
return deleteBST(&(*pRoot)->right, key);
}
完整验证代码:
#include <iostream>
using namespace std;
struct BinaryTreeNode
{
int value;
BinaryTreeNode* left, *right;
};
// 指针parent指向pRoot的父节点,其初始调用值为NULL
// 若查找成功,指针pTarget指向目标节点,函数返回true
// 否则指针pTarget指向查找路径上访问的最后一个节点,函数返回false
// pTarget初始值为NULL,由于函数调用过程中需要修改其指针值,所以参数传递双层指针
bool searchBST(BinaryTreeNode* pRoot, int key, BinaryTreeNode* parent, BinaryTreeNode** pTarget)
{
if(pRoot == NULL)
{
*pTarget = parent;
return false;
}
if(pRoot->value == key)
{
*pTarget = pRoot;
return true;
}
else if(pRoot->value > key)
return searchBST(pRoot->left, key, pRoot, pTarget);
else
return searchBST(pRoot->right, key, pRoot, pTarget);
}
// 当树为空时,需要修改根结点指针值,所以参数传递双层指针
bool insertBST(BinaryTreeNode** pRoot, int key)
{
if(*pRoot == NULL)
{
BinaryTreeNode* s = new BinaryTreeNode;
s->value = key;
s->left = s->right = NULL;
*pRoot = s;
return true;
}
else if((*pRoot)->value == key)
return false;
if((*pRoot)->value > key)
return insertBST(&(*pRoot)->left, key);
else
return insertBST(&(*pRoot)->right, key);
}
bool deleteNode(BinaryTreeNode** pRoot)
{
BinaryTreeNode* q, *s;
if((*pRoot)->left == NULL && (*pRoot)->right == NULL)
{
delete *pRoot;
*pRoot = NULL;
}
else if((*pRoot)->right == NULL)
{
q = (*pRoot)->left;
(*pRoot)->value = q->value;
(*pRoot)->left = q->left;
(*pRoot)->right = q->right;
delete q;
}
else if((*pRoot)->left == NULL)
{
q = (*pRoot)->right;
(*pRoot)->value = q->value;
(*pRoot)->left = q->left;
(*pRoot)->right = q->right;
delete q;
}
else
{
q = *pRoot;
s = (*pRoot)->left;
while(s->right)
{
q = s;
s = s->right;
}
(*pRoot)->value = s->value;
if(q != *pRoot)
q->right = s->left;
else
q->left = s->left;
delete s;
}
return true;
}
bool deleteBST(BinaryTreeNode** pRoot, int key)
{
if(*pRoot == NULL)
return false;
if((*pRoot)->value == key)
return deleteNode(pRoot);
else if((*pRoot)->value > key)
return deleteBST(&(*pRoot)->left, key);
else
return deleteBST(&(*pRoot)->right, key);
}
void printInorder(BinaryTreeNode* pRoot)
{
if(pRoot->left != NULL)
printInorder(pRoot->left);
printf("%d ", pRoot->value);
if(pRoot->right != NULL)
printInorder(pRoot->right);
}
int main()
{
int a[10] = {62, 88, 58, 47, 35, 73, 51, 99, 37, 93};
BinaryTreeNode* pRoot = NULL;
printf("Build the binary search tree:\n");
for(int i = 0; i < 10; i++)
{
insertBST(&pRoot, a[i]);
printInorder(pRoot);
printf("\n");
}
printf("which node do you want to delete?\n");
int num = 0;
while(scanf("%d", &num))
{
deleteBST(&pRoot, num);
printInorder(pRoot);
printf("\n");
}
return 0;
}
1.若b是空树,则搜索失败,否则:
2.若x等于b的根结点的数据域之值,则查找成功;否则
3.若x小于b的根结点的数据域之值,则搜索左子树:否则
4.查找右子树
// 指针parent指向pRoot的父节点,其初始调用值为NULL
// 若查找成功,指针pTarget指向目标节点,函数返回true
// 否则指针pTarget指向查找路径上访问的最后一个节点,函数返回false
// pTarget初始值为NULL,由于函数调用过程中需要修改其指针值,所以参数传递双层指针
bool searchBST(BinaryTreeNode* pRoot, int key, BinaryTreeNode* parent, BinaryTreeNode** pTarget)
{
if(pRoot == NULL)
{
*pTarget = parent;
return false;
}
if(pRoot->value == key)
{
*pTarget = pRoot;
return true;
}
else if(pRoot->value > key)
return searchBST(pRoot->left, key, pRoot, pTarget);
else
return searchBST(pRoot->right, key, pRoot, pTarget);
}
向一个二叉搜索树b中插入一个节点s的算法,过程为:
1.若b是空树,则将s所指节点作为根节点插入,否则:
2.若s->value等于b的根节点的数据域之值,则返回,否则:
3.若s->value小于b的根节点的数据域之值,则把s所指节点插入到左子树中,否则:
4.把s所指节点插入到右子树中。(新插入节点总是叶子节点)
// 当树为空时,需要修改根结点指针值,所以参数传递双层指针
bool insertBST(BinaryTreeNode** pRoot, int key)
{
if(*pRoot == NULL)
{
BinaryTreeNode* s = new BinaryTreeNode;
s->value = key;
s->left = s->right = NULL;
*pRoot = s;
return true;
}
else if((*pRoot)->value == key)
return false;
if((*pRoot)->value > key)
return insertBST(&(*pRoot)->left, key);
else
return insertBST(&(*pRoot)->right, key);
}
在二叉查找树中删去一个节点,分三种情况讨论:
1.若*p节点为叶子节点,即PL(左子树)和PR(右子树)均为空树。由于删去叶子节点不破坏整棵树的结构,则只需修改其双亲节点的指针即可。
2.若*p节点只有左子树PL或右子树PR,此时只要另PL或PR直接成为其双亲节点*f的左子树(当*p是左子树)或右子树(当*p是右子树)即可。
3.若*p节点的左子树和右子树均不空。在删去*p之后,为保持其它元素之间的相对位置不变,可按中序遍历保持有序进行调整,可以有两种做法:其一是另*p的直接前驱(inorder predecessor)或直接后继(inorder successor)替代*p,然后再从二叉查找树中删去它的直接前驱(或直接后继)
bool deleteNode(BinaryTreeNode** pRoot)
{
BinaryTreeNode* q, *s;
if((*pRoot)->left == NULL && (*pRoot)->right == NULL)
{
delete *pRoot;
*pRoot = NULL;
}
else if((*pRoot)->right == NULL)
{
q = (*pRoot)->left;
(*pRoot)->value = q->value;
(*pRoot)->left = q->left;
(*pRoot)->right = q->right;
delete q;
}
else if((*pRoot)->left == NULL)
{
q = (*pRoot)->right;
(*pRoot)->value = q->value;
(*pRoot)->left = q->left;
(*pRoot)->right = q->right;
delete q;
}
else
{
q = *pRoot;
s = (*pRoot)->left;
while(s->right)
{
q = s;
s = s->right;
}
(*pRoot)->value = s->value;
if(q != *pRoot)
q->right = s->left;
else
q->left = s->left;
delete s;
}
return true;
}
bool deleteBST(BinaryTreeNode** pRoot, int key)
{
if(*pRoot == NULL)
return false;
if((*pRoot)->value == key)
return deleteNode(pRoot);
else if((*pRoot)->value > key)
return deleteBST(&(*pRoot)->left, key);
else
return deleteBST(&(*pRoot)->right, key);
}
完整验证代码:
#include <iostream>
using namespace std;
struct BinaryTreeNode
{
int value;
BinaryTreeNode* left, *right;
};
// 指针parent指向pRoot的父节点,其初始调用值为NULL
// 若查找成功,指针pTarget指向目标节点,函数返回true
// 否则指针pTarget指向查找路径上访问的最后一个节点,函数返回false
// pTarget初始值为NULL,由于函数调用过程中需要修改其指针值,所以参数传递双层指针
bool searchBST(BinaryTreeNode* pRoot, int key, BinaryTreeNode* parent, BinaryTreeNode** pTarget)
{
if(pRoot == NULL)
{
*pTarget = parent;
return false;
}
if(pRoot->value == key)
{
*pTarget = pRoot;
return true;
}
else if(pRoot->value > key)
return searchBST(pRoot->left, key, pRoot, pTarget);
else
return searchBST(pRoot->right, key, pRoot, pTarget);
}
// 当树为空时,需要修改根结点指针值,所以参数传递双层指针
bool insertBST(BinaryTreeNode** pRoot, int key)
{
if(*pRoot == NULL)
{
BinaryTreeNode* s = new BinaryTreeNode;
s->value = key;
s->left = s->right = NULL;
*pRoot = s;
return true;
}
else if((*pRoot)->value == key)
return false;
if((*pRoot)->value > key)
return insertBST(&(*pRoot)->left, key);
else
return insertBST(&(*pRoot)->right, key);
}
bool deleteNode(BinaryTreeNode** pRoot)
{
BinaryTreeNode* q, *s;
if((*pRoot)->left == NULL && (*pRoot)->right == NULL)
{
delete *pRoot;
*pRoot = NULL;
}
else if((*pRoot)->right == NULL)
{
q = (*pRoot)->left;
(*pRoot)->value = q->value;
(*pRoot)->left = q->left;
(*pRoot)->right = q->right;
delete q;
}
else if((*pRoot)->left == NULL)
{
q = (*pRoot)->right;
(*pRoot)->value = q->value;
(*pRoot)->left = q->left;
(*pRoot)->right = q->right;
delete q;
}
else
{
q = *pRoot;
s = (*pRoot)->left;
while(s->right)
{
q = s;
s = s->right;
}
(*pRoot)->value = s->value;
if(q != *pRoot)
q->right = s->left;
else
q->left = s->left;
delete s;
}
return true;
}
bool deleteBST(BinaryTreeNode** pRoot, int key)
{
if(*pRoot == NULL)
return false;
if((*pRoot)->value == key)
return deleteNode(pRoot);
else if((*pRoot)->value > key)
return deleteBST(&(*pRoot)->left, key);
else
return deleteBST(&(*pRoot)->right, key);
}
void printInorder(BinaryTreeNode* pRoot)
{
if(pRoot->left != NULL)
printInorder(pRoot->left);
printf("%d ", pRoot->value);
if(pRoot->right != NULL)
printInorder(pRoot->right);
}
int main()
{
int a[10] = {62, 88, 58, 47, 35, 73, 51, 99, 37, 93};
BinaryTreeNode* pRoot = NULL;
printf("Build the binary search tree:\n");
for(int i = 0; i < 10; i++)
{
insertBST(&pRoot, a[i]);
printInorder(pRoot);
printf("\n");
}
printf("which node do you want to delete?\n");
int num = 0;
while(scanf("%d", &num))
{
deleteBST(&pRoot, num);
printInorder(pRoot);
printf("\n");
}
return 0;
}
相关文章推荐
- linux
- (Frontend Newbie)Web三要素(二)
- 面试题_31_to_47_JVM 底层与GC(Garbage Collection)的面试问题
- 求两个正整数的最大公约数,最小公倍数
- C#_Http(Get/Post)
- unity 定位
- android - Content-Type大全
- 深度学习(二十三)Maxout网络学习-ICML 2013
- CodeBlocks调试功能快捷教程
- MySQL 5.6 for Windows 解压缩版配置安装
- jQuery获取对象
- win10系统搭建vs2015+cocos2d-x 3.9开发环境
- 机器学习公开课笔记(5):神经网络(Neural Network)——学习
- Effective C++ (item1、item 2)
- 关于有偿提供拼图响应式后台的通知
- [六]JFreeChart实践五之与Struts2整合
- (C#) Tasks 中的异常处理(Exception Handling.)
- xCode中如何安装旧的模拟器
- 基于HTML5的Web SCADA工控移动应用
- Linux学习第四周