【发布时间】：2015-07-05 22:11:29
【问题描述】：
鉴于以下代码，我可以使用什么来创建删除功能？我已经尝试了很多事情，但我一直在试图让它发挥作用。我的主要问题是尝试删除具有左右子节点的节点。对于没有子节点的节点，我可以将其父节点设置为 null 并释放节点。对于一个孩子，只需将父母设置为指向孩子并释放节点。对于一个在概念上和代码中都有两个孩子的节点，我该如何做？
#include<stdlib.h>
#include<stdio.h>
struct bin_tree {
int data;
struct bin_tree * right, * left;
} bin_tree;
typedef struct bin_tree node;
void help()//help
{
printf("Options:\n");
printf(" # -Put in any number to add it to the tree if not already there\n");
printf(" s # -Put in s and a number to search the tree for the number\n");
printf(" d # -Delete the number from the tree\n");
printf(" p -Put in p to print the tree\n");
printf(" ? -At any time you can press ? to display the help message\n");
printf(" Q -If you decide the leave the realm of the tree then you can press Q to quit this program\n");
}
int max(int a,int b)//max tree length
{
if(a>b)
return a;
else
return b;
}
int height(node* tree)//height
{
if(tree != NULL)
return(1 + max(height(tree->left),height(tree->right)));
else
return 0;
}
void insert(node ** tree, int val)//insert
{
node *temp = NULL;
if(!(*tree))
{
temp = (node *)malloc(sizeof(node));
temp->left = temp->right = NULL;
temp->data = val;
*tree = temp;
return;
}
if(val < (*tree)->data)
{
insert(&(*tree)->left, val);
}
else if(val > (*tree)->data)
{
insert(&(*tree)->right, val);
}
}
void print(node * tree)//print
{
if (tree)
{
print(tree->left);
printf("[%d] ",tree->data);
print(tree->right);
}
}
node* search(node ** tree, int val)
{//search
if(!(*tree))
{
return NULL;
}
if(val < (*tree)->data)
{
search(&((*tree)->left), val);
}
else if(val > (*tree)->data)
{
search(&((*tree)->right), val);
}
else if(val == (*tree)->data)
{
return *tree;
}
}
void main()
{
node *root;
node *tmp;
int no;
char ch, buff[500];
root = NULL;
printf("Options:\n");
printf(" # -Put in any intiger to add it to the tree if not already there\n");
printf(" s # -Put in s and a number to search the tree for the number\n");
printf(" d # -Delete the number from the tree\n");
printf(" p -Print the tree\n");
printf(" ? -At any time you can press ? to display the help message\n");
printf(" Q -If you decide the leave the realm of the tree then you can press Q to quit this program\n");
while(1){
printf(">");
fgets(buff,499,stdin); //grabs input from user
if(sscanf(buff,"%i",&no)==1){//decides if just a number
tmp = search(&root, no);//looks for number in the tree
if (tmp)
{
printf("Node already in tree!\n", tmp->data);
}
else
{
insert(&root, no);//if not in tree insert it
}
}
else if(sscanf(buff,"%c %i",&ch,&no)>=1)//checks if character
{
switch(ch)
{
case 's'://search for number
{
tmp = search(&root, no);
if (tmp)
{
printf("Node found=%d\n", tmp->data);
}
else
{
printf("Node not found in tree.\n");
}
break;
}
case 'd':
tmp = search(&root, no);
if (tmp)
{
//Call delete function
printf("Node %i deleted", no);
break;
}
else
{
printf("Node not found in tree.\n");
break;
}
case 'Q'://quit
exit(0);
case 'p'://print tree
printf("\n\n");
print(root);
printf("\nHeight= %i\n\n",height(root));
break;
case '?'://display help
help();
break;
default://idiot >.>
printf("Invalid input!\n\n");
help();
break;
}
}
}
return;
}
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