平衡二叉树

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

#define LH 1//左高
#define EH 0//等高
#define RH -1//右高
#define TRUE 1
#define FALSE 0
#define OK 1
#define ERROR 0

typedef int ElemType;
typedef int Status;
typedef int Boolean;

typedef struct BSTNode{
ElemType data;
int bf;//节点的平衡因子
struct BSTNode *lchild,*rchild;
}BSTNode,*BSTree;

void R_Rotate(BSTree &p);
void L_Rotate(BSTree &p);
void LeftBalance(BSTree &T);
void RightBalance(BSTree &T);
Status InsertAVL(BSTree &T,ElemType e,Boolean &taller);
void PreOrderTraverse(BSTree p);

int main()
{
BSTree T=NULL;
int n,m;
Boolean taller;
printf("输入二叉树节点数:");
scanf("%d",&n);
for(int i=0;i<n;i++)
{
scanf("%d",&m);
InsertAVL(T,m,taller);
}
PreOrderTraverse(T);
return 0;
}

Status InsertAVL(BSTree &T,ElemType e,Boolean &taller)
{
if(!T)
{
T=(BSTNode*)malloc(sizeof(BSTNode));
if(!T)exit(0);
T->data=e;
T->lchild=T->rchild=NULL;
taller=TRUE;
T->bf=EH;
}
else
{
if(e==T->data)//子树没有增长
{
taller=FALSE;
return FALSE;
}
else if(e<T->data)
{
if(InsertAVL(T->lchild,e,taller))
if(taller)
{
switch (T->bf)
{
case LH:
LeftBalance(T);
taller=FALSE;
break;
case EH:
T->bf=LH;
taller=TRUE;
break;
case RH:
T->bf=EH;
taller=FALSE;
break;
}

}
}
else
{
if(InsertAVL(T->rchild, e, taller))
if(taller)
{
switch(T->bf)
{
case LH:
T->bf = EH;
taller = FALSE;
break;

case EH:
T->bf = RH;
taller = TRUE;
break;

case RH:
RightBalance(T);
break;
}
}
}
}
return OK;
}

void LeftBalance(BSTree &T)
{
BSTree lc,rd;
lc=T->lchild;
switch (lc->bf)//因为要平衡，所以平衡因子不可能为0
{
case LH:
T->bf=lc->bf=EH;
R_Rotate(T);
break;
case RH:
T->bf=lc->bf=EH;
L_Rotate(T->lchild);
R_Rotate(T);
}

}

void RightBalance(BSTree &T)
{
BSTree rc,ld;
rc=T->rchild;
switch (rc->bf)
{
case LH:
ld=rc->lchild;
T->bf=rc->bf=ld->bf;
R_Rotate(T->rchild);
L_Rotate(T);
break;
case RH:
T->bf=rc->bf=EH;
L_Rotate(T);
break;
}

}

void R_Rotate(BSTree &p)
{
BSTree rc;
rc=p->lchild;
p->lchild=rc->rchild;
rc->rchild=p;
p=rc;
}

void L_Rotate(BSTree &p)
{
BSTree lc;
lc=p->rchild;
p->rchild=lc->lchild;
lc->lchild=p;
p=lc;
}

void PreOrderTraverse(BSTree p)
{
if(p)
{
printf("%d ",p->data);
PreOrderTraverse(p->lchild);
PreOrderTraverse(p->rchild);
}
}