二叉树常用算法

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

#define		MAX 100
typedef struct Node{
	int data;
	struct Node *lchild,*rchild;
}BiTNode,*BiTree;
void buildTree(BiTree *T){
	char ch;
	scanf("%c",&ch);
//	printf("%c\n",ch);
	if(ch=='#')
		*T=NULL;
	else{
		*T=(BiTNode*)malloc(sizeof(BiTNode));
		(*T)->data=ch;
		buildTree(&(*T)->lchild);
		buildTree(&(*T)->rchild);
	}
}

void pre_order(BiTNode *p){
	if(p){
		printf("%c ",p->data);
		pre_order(p->lchild);
		pre_order(p->rchild);
	}
}
void pre_tranvese(BiTNode *T){
	BiTree	stack[MAX];
	int		top=-1;
	BiTree	p=T;
	if(p==NULL) return;
	while(p||top>=0){
		while(p){
			printf("%c ",p->data);
			stack[++top]=p;
			p=p->lchild;
		}
		p=stack[top--];
		p=p->rchild;
	}
	printf("\n");
}
//中序遍历
void in_order(BiTree T){
	if(T){
		in_order(T->lchild);
		printf("%c ",T->data);
		in_order(T->rchild);
	}
}
void in_tranvese(BiTree T){
	BiTree	stack[MAX];
	int		top=-1;
	BiTree	p=T;
	if(p==NULL) return;
	while(p||top>=0){
		while(p){
			stack[++top]=p;
			p=p->lchild;
		}
		p=stack[top--];
		printf("%c ",p->data);
		p=p->rchild;
	}
	printf("\n");
}
//后序遍历
void post_order(BiTree T){
	if(T){
		post_order(T->lchild);
		post_order(T->rchild);
		printf("%c ",T->data);
	}
}
void post_tranvese(BiTree T){
	BiTree	stack[MAX];
	int		top=-1;
	BiTree	p=T,pre=NULL;
	while(p||top>=0){
		while(p){
			stack[++top]=p;
			p=p->lchild;
		}
		p=stack[top];
		//p没有右孩子或者右孩子已经访问过直接访问p
		if(p->rchild==NULL||p->rchild==pre){
			printf("%c ",p->data);
			pre=p;
			p=NULL;//p要设置为空 
			top--;
		}else{
			p=p->rchild;
		}
	}
	printf("\n");
}
int height(BiTree T){
	int left,right;
	if(!T) return 0;
	left=height(T->lchild)+1;
	right=height(T->rchild)+1;
	return left>right ? left : right;
}

int leaf_count(BiTree T){
	if(T==NULL) return 0;
	if(T->lchild==NULL&&T->rchild==NULL) return 1;
	return leaf_count(T->lchild)+leaf_count(T->rchild);
}

int nonleaf_count(BiTree T){
	if(T==NULL) return 0;
	if(T->lchild==NULL&&T->rchild==NULL) return 0;
	//if(T->lchild!=NULL||T->rchild!=NULL) return 1;
	return nonleaf_count(T->lchild)+nonleaf_count(T->rchild)+1;
}
//先序 中序 创建树
void build_pre_in(BiTree *T,char *pre,char *in,int len){
	char *temp;
	int k;
	if(len<=0) {
		*T=NULL;
		return;
	}
	for(temp=in;temp<in+len;temp++){
		if(*temp==*pre){
			*T=(BiTNode*)malloc(sizeof(BiTNode));
			(*T)->data=*temp;
			k=temp-in;
			break;
		}
	}
	build_pre_in(&((*T)->lchild),pre+1,in,k);
	build_pre_in(&((*T)->rchild),pre+k+1,temp+1,len-k-1);
}
//中序 后序  创建树
void build_in_post(BiTree *T,char *in,char *post,int len){
	char *temp;
	int k;
	if(len<=0){
		*T=NULL;
		return;
	}
	for(temp=in;temp<in+len;temp++){
		if(*temp==*(post+len-1)){
			*T=(BiTNode*)malloc(sizeof(BiTNode));
			(*T)->data=*temp;
			k=temp-in;
			//printf("%c \n",*temp);
			break;
		}
	}
	build_in_post(&((*T)->lchild),in,post,k);
	build_in_post(&((*T)->rchild),temp+1,post+k,len-k-1);
}

//中序 后序 -->先序
void in_post_pre(char *in,char *post,int len){
	char *temp;
	int	  k;
	if(len<=0) return;
	for(temp=in;temp<in+len;temp++){
		if(*temp==*(post+len-1)){
			printf("%c ",*temp);
			k=temp-in;
			break;
		}
	}
	in_post_pre(in,post,k);
	in_post_pre(temp+1,post+k,len-k-1);
}

void main(){
	char *pre=	"ABDGEHICFJ";
	char *in=	"DGBHEIAFJC";
	char *post=	"GDHIEBJFCA";
	BiTree T;
	//freopen("1.txt","r",stdin);
	//buildTree(&T);
	//build_pre_in(&T,pre,in,strlen(in));
	build_in_post(&T,in,post,strlen(in));
	printf("Pre Order:\n");
	pre_order(T);
	printf("\n");
	pre_tranvese(T);
	printf("In Order:\n");
	in_order(T);
	printf("\n");
	in_tranvese(T);
	printf("Post Order:\n");
	post_order(T);
	printf("\n");
	post_tranvese(T);
	printf("height of tree: %d\n",height(T));
	printf("leaf count of tree:%d\n",leaf_count(T));
	printf("non leaf count of tree:%d\n",nonleaf_count(T));
	printf("in post-->pre\n");
	in_post_pre(in,post,strlen(in));
	printf("\n");
}