程序代码：

#include "stdio.h"
#include "malloc.h"
#include "string.h"
#define TRUE 1
#define FALSE 0
#define OK  1
#define ERROR  0
#define INFEASIBLE -1
#define OVERFLOW -2
typedef int  Status;

typedef char  ElemType;
typedef struct BiTNode{
  ElemType data;
  struct BiTNode *lchild,*rchild;//左右孩子指针
} BiTNode,*BiTree;

BiTree PreCreate(char *post,char *in,int len)
{
    int leftlen,rightlen;
    char *p;
    BiTree root;
    if(len<=0)
        return NULL;
    root=(BiTNode *)malloc(sizeof(BiTNode));
    root->data=post[len-1];
//    printf("%c",root->data);
    for(p=in;p-in<len;p++)
    {
        if(*p==root->data)
        break;
    }
    leftlen=p-in;
    rightlen=len-leftlen-1;
    root->lchild=PreCreate(post+1,in,leftlen);
    root->rchild=PreCreate(post+leftlen+1,p+1,rightlen);
    return root;
}

void print(BiTree T)  // 打印后序遍历序列
{
    if(T==NULL) return;
    print(T->lchild);
    print(T->rchild);
    printf("%c",T->data);

}
int main()
{

  int len=6;
  char post[6]={'d','e','b','f','c','a'},in[6]={'d','b','e','a','f','c'};    // 存储后序和中序遍历的序列
  BiTree T;
  T=(BiTNode *)malloc(sizeof(BiTNode));
  T=PreCreate(post,in,len);
    print(T);
    printf("\n");


  return 0;

}