满二叉树根据前序求后序

#include <cstdio>  #include <iostream>using namespace std;#define N 100void pre2post(char pre[] , int preL,int preR , char post[] , int postL , int postR){    if(preL <= preR)    {        post[postR] = pre[preL];        int halfpos = (preR - preL) / 2; // 数量对半分        pre2post(pre , preL+1 , preL + halfpos, post , postL ,postL + halfpos  - 1); // 左        pre2post(pre , preL+halfpos+1 , preR, post , postL + halfpos ,postR-1); // 右    }}int main()  {      //freopen("in.txt","r",stdin);    /*              A            /   \           B     C          / \   / \         D   E  F  G    */    char pre[N] = "ABDECFG";    char post[N]; // D E B F G C A     pre2post(pre,0,6, post, 0 ,6);    for(int i = 0 ; i <= 6 ; i ++)    {        printf("%c ", post[i]);    }    return 0;  }