test/DispBiTree.cpp

#include<stdio.h>
#include<malloc.h>
#define MaxSize 30
typedef char ElemType;
typedef struct node
{
	ElemType data;
	struct node *lchild;
	struct node *rchild;
}BTNode;
typedef struct{
	BTNode* data[MaxSize];
	int top;
}SqStack;

void InitStack(SqStack *&s){
	s = (SqStack*)malloc(sizeof(SqStack));
	s->top = -1;
}
bool StackEmpty(SqStack *s){
	return(s->top == -1);
}
bool Push(SqStack *&s,BTNode *e){
	if(s->top == MaxSize-1)
		return false;
	s->top++;
	s->data[s->top] = e;
	return true;
}
bool Pop(SqStack *&s,BTNode *&e){
	if(s->top == -1)
		return false;
	e = s->data[s->top];
	s->top--;
	return true;
}
int CreateBiTree(BTNode *&T,char *str){
	BTNode *St[MaxSize],*p;
	int top = -1,k,j = 0;
	char ch;
	T = NULL;
	ch = str[j];
	while(ch!='\0')
	{
		switch(ch)
		{
		case '(':top++;St[top]=p;k=1;break;
		case ')':top--;break;
		case ',':k=2;break;
		default:p=(BTNode *)malloc(sizeof(BTNode));
			    p->data=ch;p->lchild=p->rchild=NULL;
				if(T==NULL)
					T=p;
				else
				{
					switch(k)
					{
					case 1:St[top]->lchild=p;break;
					case 2:St[top]->rchild=p;break;
					}
				}
		}
		j++;
		ch=str[j];
	}
	return 0;
}
int preOrder(BTNode *T){
	if(T != NULL){
		printf("%c",T->data);
		preOrder(T->lchild);
		preOrder(T->rchild);
	}
}
int inOrder(BTNode *T){
	if(T != NULL){
		inOrder(T->lchild);
		printf("%c",T->data);
		inOrder(T->rchild);
	}
}
int postOrder(BTNode *T){
	if(T != NULL){
		postOrder(T->lchild);
		postOrder(T->rchild);
		printf("%c",T->data);
	}
}

void ldr(BTNode *T){
	BTNode *p;
	SqStack *st;
	InitStack(st);
	p = T;
	while(!StackEmpty(st) || p != NULL){
		while(p != NULL){
			Push(st,p);
			p = p->lchild;
		}
		if(!StackEmpty(st)){
			Pop(st,p);
			printf("%c",p->data);
			p = p->rchild;
		}
	}
}
int main(){
	BTNode *T = NULL;
	char str[30];
	int option;
	
	do{
		printf("Options:\n");
		printf("%-25s%-25s%-25s\n%-25s%-25s%-25s\n","1.CreateBTree","2.PreOrder Result","3.InOrder Result","4.PostOrder Result","5.ldr Result","6.Quit");
		scanf("%d",&option);
		switch(option){
			case 1:
				printf("Input string:\n");
				scanf("%s",str);	
				CreateBiTree(T,str);
				break;
			case 2:
				if(T == NULL) break;
				printf("PreOrder:\n");
				preOrder(T);
				printf("\n");
				break;
			case 3:
				if(T == NULL) break;
				printf("InOrder:\n");
				inOrder(T);
				printf("\n");
				break;
			case 4:
				if(T == NULL) break;
				printf("PostOrder\n");
				postOrder(T);
				printf("\n");
				break;
			case 5:
				if(T == NULL) break;
				printf("INORDER:\n");
				ldr(T);
				printf("\n");
				break;
			case 6:
				return 0;
		}
		printf("\n");
	}while(true);
}