#include<stdlib.h>
#include<stdio.h>
typedef struct treenode
{
int data;
struct treenode *left;
struct treenode *right;
}tnode;
tnode * insert(tnode *node,int data)
{
if(node==NULL)
{
node=(tnode *)malloc(sizeof(tnode));
node->data=data;
node->left=node->right=NULL;
return node;
}
if(data>node->data)
{
node->right=insert(node->right,data);
}
else if(data<node->data)
{
node->left=insert(node->left,data);
}
return node;
}
tnode * find(tnode *node,int data)
{
if(node==NULL)
return NULL;
if(node->data<data)
return find(node->right,data);
else if(node->data>data)
return find(node->left,data);
else
return node;
}
tnode* maximal(tnode *node)
{
if(node==NULL)
{
return NULL;
}
if(node->right)
return maximal(node->right);
else
return node;
}
tnode* minimal(tnode *node)
{
if(node==NULL)
{
return NULL;
}
if(node->left)
return minimal(node->left);
else
return node;
}
tnode * delete(tnode *node,int data)
{
tnode *temp;
if(node==NULL)
{
printf("Element Not Found");
}
else if(data < node->data)
{
node->left = delete(node->left, data);
}
else if(data > node->data)
{
node->right = delete(node->right, data);
}
else
{
/* Now We can delete this node and replace with either minimum element
in the right sub tree or maximum element in the left subtree */
if(node->right && node->left)
{
/* Here we will replace with minimum element in the right sub tree */
temp = minimal(node->right);
node -> data = temp->data;
/* As we replaced it with some other node, we have to delete that node */
node -> right = delete(node->right,temp->data);
}
else
{
/* If there is only one or zero children then we can directly
remove it from the tree and connect its parent to its child */
temp = node;
if(node->left == NULL)
node = node->right;
else if(node->right == NULL)
node = node->left;
free(temp); /* temp is longer required */
}
}
return node;
}
int main()
{
tnode *root=NULL,*temp;
//int maximum,minimum;
int op,n;
do
{
printf("\n1.insertion");
printf("\n2.deletion");
printf("\n3.preorder");
printf("\n4.inorder");
printf("\n5.postorder");
printf("\n6.minimal node");
printf("\n7.maximum node");
printf("\n8.find node");
printf("\n9.quit");
printf("\nenter your option:");
scanf("%d",&op);
switch(op)
{
case 1:
printf("enter the element to be inserted:");
scanf("%d",&n);
root=insert(root,n);
break;
case 2:
printf("enter the element to be deleted:");
scanf("%d",&n);
root=delete(root,n);
break;
case 6:
temp=minimal(root);
if(temp==NULL)
printf("no elements in the tree");
else
printf("the minimum element found is:%d",temp->data);
break;
case 7:
temp=maximal(root);
if(temp==NULL)
printf("no elements in the tree");
else
printf("the maximal element found is:%d",temp->data);
break;
case 8:
printf("enter the element to be found:");
scanf("%d",&n);
temp=find(root,n);
if(temp == NULL)
printf("element not found");
else
printf("element found");
break;
default :
exit(0);
}
}while(op<9);
return 0;
}
*当我编译时，很多错误都在打击我，所有错误都与删除函数以及如何释放指针有关（两个错误与释放指针有关）。我在寡妇平台上使用 gcc 来执行程序。*
错误如下： g++.exe -x c++ -c C:\Users\HARSHA\DOCUME~1\GCCPRO~1\ps2\BINARY~2.C -o C:\Users\HARSHA\DOCUME~1\GCCPRO ~1\ps2\BINARY~2.o -Wall -fpermissive C:\Users\HARSHA\DOCUME~1\GCCPRO~1\ps2\BINARY~2.C:97：在“删除”之前解析错误
C:\Users\HARSHA\DOCUME~1\GCCPRO~1\ps2\BINARY~2.C:120: `->' 之前的语法错误
C:\Users\HARSHA\DOCUME~1\GCCPRO~1\ps2\BINARY~2.C:122: `->' 之前的语法错误
C:\Users\HARSHA\DOCUME~1\GCCPRO~1\ps2\BINARY~2.C:133: `temp' 未在此范围内声明
C:\Users\HARSHA\DOCUME~1\GCCPRO~1\ps2\BINARY~2.C:133：警告：ANSI C++ 禁止无类型声明“免费”
C:\Users\HARSHA\DOCUME~1\GCCPRO~1\ps2\BINARY~2.C:133: `int free' 重新声明为不同类型的符号
...\lib\gcc-lib\i386-mingw32\2.95.2........\include\stdlib.h:271: 先前声明的 `void free(void *)'
C:\Users\HARSHA\DOCUME~1\GCCPRO~1\ps2\BINARY~2.C:134: `}' 之前的解析错误
C:\Users\HARSHA\DOCUME~1\GCCPRO~1\ps2\BINARY~2.C：在函数“int main()”中：
C:\Users\HARSHA\DOCUME~1\GCCPRO~1\ps2\BINARY~2.C:174：警告：逗号表达式的左侧操作数无效
C:\Users\HARSHA\DOCUME~1\GCCPRO~1\ps2\BINARY~2.C:174：类型int' argument given to删除'，预期指针
失败