排序树的删除节点

最新推荐文章于 2024-06-21 18:03:58 发布

原创最新推荐文章于 2024-06-21 18:03:58 发布 · 425 阅读

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CC 4.0 BY-SA版权

本文提供了一个使用C语言实现的二叉搜索树(BST)实例，包括插入、中序遍历及删除节点等功能。通过具体代码展示了如何创建、操作及维护一棵二叉树。

#include <stdio.h>
#include <stdlib.h>

typedef struct _Tree
{
int nValue;
struct _Tree* pLeft;
struct _Tree* pRight;
}Tree;

void InsertTree(Tree** tree,int nInsertValue)
{
if (*tree == NULL)
{
  (*tree) = (Tree*)malloc(sizeof(Tree));
  (*tree)->nValue = nInsertValue;
  (*tree)->pLeft = NULL;
  (*tree)->pRight = NULL;
  return;
}
else       // 看这个值要放在左边还是右边
{
  //Tree* temp = (*tree);

  while(1)
  {
   if ((*tree)->nValue < nInsertValue)
   {
    if ((*tree)->pRight == NULL)
    {
     (*tree)->pRight = (Tree*)malloc(sizeof(Tree));
     (*tree)->pRight->nValue = nInsertValue;
     (*tree)->pRight->pLeft = NULL;
     (*tree)->pRight->pRight = NULL;
     return;
    }
    //(*tree) = (*tree)->pRight;
    tree = &((*tree)->pRight);
   }
   else
   {
    if ((*tree)->pLeft == NULL)
    {
     (*tree)->pLeft = (Tree*)malloc(sizeof(Tree));
     (*tree)->pLeft->nValue = nInsertValue;
     (*tree)->pLeft->pLeft = NULL;
     (*tree)->pLeft->pRight = NULL;
     return;
    }
    //(*tree) = (*tree)->pLeft;
    tree = &((*tree)->pLeft);
   }
  }
}
}

void CreateTree(Tree** tree,int* arr,int nLength)
{
for (int i=0;i<nLength;i++)
{
InsertTree(tree,arr[i]);
}
}

void DeleteOneChild(Tree* pDel,Tree* pFather)
{
// 看要删除的节点是放在他父亲节点的左边还是右边
if (pDel == pFather->pLeft)
{
  // 让左指针指向他不为空的那个子节点
  pFather->pLeft = pDel->pLeft?pDel->pLeft:pDel->pRight;
}
else
{
  pFather->pRight = pDel->pLeft?pDel->pLeft:pDel->pRight;
}
free(pDel);
pDel = NULL;
}

void FindTree(Tree* tree,int nFindValue,Tree** pDel,Tree** pFather)
{
while(tree)
{
  if (tree->nValue == nFindValue)
  {
   // 记住要删除的这个节点
   (*pDel) = tree;
   return;
  }
  else if (tree->nValue > nFindValue)    // 在左边查找
  {
   *pFather = tree;
   tree = tree->pLeft;
  }
  else
  {
   *pFather = tree;
   tree = tree->pRight;
  }
}

*pDel = NULL;
*pFather = NULL;
}

void DeleteTree(Tree** tree,int nDeleteValue)
{
if ((tree == NULL) || (*tree == NULL))
{
return;
}
Tree* pDel = NULL;
Tree* pFather = NULL;

// 查找要删除的节点
FindTree(*tree,nDeleteValue,&pDel,&pFather);

// 看是不是查找成功
if(pDel == NULL)
{
return;
}

// 看要删除的节点有几个子节点
if (pDel->pLeft != NULL && pDel->pRight != NULL)
{
  Tree* bj = pDel;
  pFather = pDel;
  // 把它转换成只有一个子节点的情况
  pDel = pDel->pRight;

  while(pDel->pLeft)
  {
   pFather = pDel;
   pDel = pDel->pLeft;
  }

  //pDel 记住的就是要替换值的那个节点
  bj->nValue = pDel->nValue;
}

// 看要删除的是不是根
if (pFather == NULL)
{
  (*tree) = pDel->pLeft?pDel->pLeft:pDel->pRight;
  free(pDel);
  pDel = NULL;
  return;
}
// 删除只有一个子节点
DeleteOneChild(pDel,pFather);
}

void MidPrint(Tree* tree)
{
if (tree)
{
  MidPrint(tree->pLeft);
  printf("%d ",tree->nValue);
  MidPrint(tree->pRight);
}
}

int main()
{

int arr[10] = {5,6,2,3,1,9,8,0,7,4};

Tree* tree = NULL;

CreateTree(&tree,arr,10);

MidPrint(tree);
printf("\n");

DeleteTree(&tree,0);

MidPrint(tree);
printf("\n");

system("pause");
return 0;
}