C语言二叉查找树问题，在 return searchBST( T->rchild, val, f, p); 处出错，求教出错原理，这里应该涉及了双重指针的问题，我理不清。
#include <stdio.h>
#include <malloc.h>
#define OK 1
#define TRUE 1
#define ERROR -1
#define FALSE 0
typedef int ElemType;
typedef struct Node
{
ElemType data;
struct Node *lchild,*rchild;
}NODE,*PNODE;
//prompt error info and exit.
void errorInfo(char str[])
{
printf("%s\n",str);
exit(-1);
}
//prompt error if there is an error in locating memory
void mallocErr(PNODE p)
{
if(NULL==p)
errorInfo("Error in locating memory.");
}
//search binary sort tree
int searchBST(PNODE T,int val,PNODE *f,PNODE *p)
{
if(!T)
{
*p = *f;
return FALSE;
}
else if(val == T->data)
{
*p = T;
return TRUE;
}else if(val < T->data)
{
printf("run this code 52\n");
*f = T;
return searchBST(T->lchild,val,f,p);
}else
{
printf("run this code 56\n");
*f = T;
printf("run this code 58\n");
printf("T->data : %d \n",T->data);
//运行到此处出错
return searchBST( T->rchild, val, f, p);
}
}
int insertBST(PNODE *T,int val)
{
PNODE p = NULL, s = NULL,f = NULL;
int res = 0;
res = searchBST(*T,val,&f,&p);
if(!res) //val does not exist in the array.
{
s = (PNODE)malloc(sizeof(NODE));
mallocErr(s);
s->data = val;
if(!p) //p is null
{
printf("run this code 75\n");
printf("Create Tree with val:%d\n",val);
*T = s;
}else if(val < p->data)
{
printf("run this code 79\n");
printf("Insert Key To Tree(left):%d\n",val);
p->lchild = s;
}else
{
printf("run this code 84\n");
printf("Insert Key To Tree(right):%d\n",val);
p->rchild = s;
}
return TRUE;
}else //val already exists in the array.
{
return FALSE;
}
}
int main()
{
PNODE T = NULL, p = NULL;
insertBST(&T,100);
insertBST(&T,199);
return 0;
}
SapereAudor
相关分类