满二叉树通过先序遍历数组求后序遍历数组

#include <stdio.h>
/****
 * 此算法为满二叉树通过先序遍历数组获得后序遍历数组
 ***/ 
// a[]为pre数组，b[]为post数组
void get_lrn_by_nlr(char a[], int a_left, int a_right, char b[], int b_left, int b_right)
{
    if (a_right >= a_left)
    {
        b[b_right] = a[a_left];
        get_lrn_by_nlr(a, a_left + (a_right - a_left) / 2 + 1, a_right, b, b_left + (b_right - b_left) / 2, b_right - 1);
        get_lrn_by_nlr(a, a_left + 1, a_left + (a_right - a_left) / 2, b, b_left, b_left + (b_right - b_left) / 2 - 1);
    }
}

int main()
{
    char a[] = {'A', 'B', 'C', 'D', 'E', 'F', 'G'}, b[7];
    get_lrn_by_nlr(a, 0, 6, b, 0, 6);
    for (int i = 0; i < 7; i++)
        printf("%c ", b[i]);
    return 0;
}