二叉树遍历：已知前序和中序，求后序

#include <stdio.h>

#include <stdlib.h>

#include <string.h>



#define MAX 1000



typedef struct node{

	char d;

	struct node *lchild,*rchild;

}Tnode;



void MK(char in[],int is,int ie,char pre[],int pres,int pree,Tnode **r){

	int i;

	if(is>ie||pres>pree){

		*r=NULL;

	}else{

		*r=(Tnode*)malloc(sizeof(Tnode));

		(*r)->d=pre[pres];//前序的第一个节点把中序分为左右子树

		for(i=is;i<=ie;i++){

			if(in[i]==pre[pres]){

				MK(in,is,i-1,pre,pres+1,pres+i-is,&(*r)->lchild);

				MK(in,i+1,ie,pre,pres+i-is+1,pree,&(*r)->rchild);

				break;

			}

		}

	}

}





void porder(Tnode *r){

	if(r){

		porder(r->lchild);

		porder(r->rchild);

		printf("%c",r->d);

	}

}





int leaf(Tnode *r){

	if(r==NULL){

		return 0;

	}else{

		if(!r->lchild&&!r->rchild){

			return 1;

		}else 

		return leaf(r->lchild)+leaf(r->rchild);

	}

}



int high(Tnode *r){

	int h1,h2;

	if(r==NULL){

		return 0;

	}else{

		h1=high(r->lchild);

		h2=high(r->rchild);

		return 1+(h1>h2?h1:h2);

	}

}



void main(){

	Tnode *r = NULL;

	char in[MAX],pre[MAX];

	printf("请输入前序序列：");

	gets(pre);

	printf("请输入中序序列：");

	gets(in);



	MK(in,0,strlen(in)-1,pre,0,strlen(pre)-1,&r);



	porder(r);



	printf("叶子节点的个数为：%d\n",leaf(r));

	printf("二叉树的高度为：：%d\n",high(r));

}