求一个关于二叉树非递归遍历的程序

Question

要求是这样的，先人工输入一个n值，然后生成一个n层的满二叉树，输出。再输入1，2，3，分别代表非递归先序，中序，后序遍历，按输入的方法遍历后输出，谢谢大家！！！！

Answer 1

#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
#define STACK_INIT_SIZE 100
#define STACKINCREMENT 10
typedef struct BiTNode
{
char data;
struct BiTNode *lchild,*rchild;
}
BiTNode,*BiTree;
typedef struct SqStack
{
BiTNode *base;
BiTNode *top;
int stacksize;
}
SqStack;
void InitStack(SqStack *S)
{
S->base=(BiTNode*)malloc(STACK_INIT_SIZE*sizeof(BiTNode));
S->top=S->base;
S->stacksize=STACK_INIT_SIZE;
}
void Push(SqStack *S,BiTNode e)
{
if(S->top-S->base>=S->stacksize)
{
S->base=(BiTNode*)realloc(S->base,
(S->stacksize+STACKINCREMENT)*sizeof(BiTNode));
S->top=S->base+S->stacksize;
S->stacksize+=STACKINCREMENT;
}
*(S->top)=e;
S->top++;
}
BiTNode Pop(SqStack *S)
{
S->top --;
return *S->top;

}
int StackEmpty(SqStack *S)
{
if(S->top == S->base )
return 1;
else
return 0;
}
BiTree CreateBiTree()
{
char p;BiTree T;
scanf("%c",&p);
if(p==' ')
T=NULL;
else
{
T=(BiTNode *)malloc(sizeof(BiTNode));
T->data=p;
T->lchild=CreateBiTree(T->lchild);
T->rchild=CreateBiTree(T->rchild);
}
return (T);
}
void PreOrder(BiTree T)//先序
{
SqStack S;
BiTree p=T;
InitStack(&S);
if(p)
Push(&S,*p);
while(!StackEmpty(&S))
{
p=(BiTNode *)malloc(sizeof(BiTNode));
*p=Pop(&S);
printf("%c",p->data);
if(p->rchild)
Push(&S,*p->rchild);
if(p->lchild)
Push(&S,*p->lchild);
}
}

void InOrder(BiTree T)//中序
{
SqStack S;
BiTree p=T;
InitStack(&S);
while(p||!StackEmpty(&S))
{
if(p)
{
Push(&S,*p);
p=p->lchild;
}
else
{
p=(BiTNode *)malloc(sizeof(BiTNode));
*p=Pop(&S);
printf("%c",p->data);
p=p->rchild;
}
}
}

void PostOrder(BiTree T)//后序
{
SqStack S;
BiTNode p, *l, *r;
InitStack(&S);
Push(&S, *T);
while(!StackEmpty(&S))
{
p = Pop(&S);
l = p.lchild;
r = p.rchild;
if (l == NULL && r == NULL)
{
printf("%c", p.data);
}
else
{
p.lchild = NULL;
p.rchild = NULL;
Push(&S, p);
if (r != NULL) Push(&S, *r);
if (l != NULL) Push(&S, *l);
}
}
}

void main()
{
BiTree Ta;int a;
printf("请创建树");
Ta=CreateBiTree();
printf("请选择：\n");
scanf("%d",&a);
if(a==1)
{
printf("先序遍历:");
printf("\n");
PreOrder(Ta);
}
if(a==2)
{
printf("中序遍历:");
printf("\n");
InOrder(Ta);
}
if(a==3)
{
printf("后序遍历:");
printf("\n");
PostOrder(Ta);
}

}