给大火看看我无聊的课后作业

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

typedef struct TreeNode
{
    char data;
    struct TreeNode* leftchild;
    struct TreeNode* rightchild;
}TreeNode, *BitTree;

inline BitTree CreateBitTree1(char *pa, char *la, int p1, int p2, int i1, int i2)
{
    int k = 0;
    while (i1 + k <= i2 && pa[p1] != la[i1 + k]) k ++;
    if (i1 + k > i2) return NULL;
    BitTree tree = new TreeNode;
    tree -> data = pa[p1];
    tree -> leftchild = CreateBitTree1(pa, la, p1 + 1, p1 + k, i1, i1 + k - 1);
    tree -> rightchild = CreateBitTree1(pa, la, p1 + k + 1, p2, i1 + k + 1, i2);
    return tree;
}

inline BitTree CreateBitTree2(char *pa, char *la, int p1, int p2, int i1, int i2)
{
    int k = 0;
    while (i1 + k <= i2 && pa[p2] != la[i1 + k]) k ++;
    if (i1 + k > i2) return NULL;
    BitTree tree = new TreeNode;
    tree -> data = pa[p2];
    tree -> leftchild = CreateBitTree2(pa, la, p1, p1 + k - 1, i1, i1 + k - 1);
    tree -> rightchild = CreateBitTree2(pa, la, p1 + k, p2 - 1, i1 + k + 1, i2);
    return tree;
}

inline void PrintPostTravel(BitTree tree)
{
  if (tree == NULL) return ;
  if (tree -> leftchild) PrintPostTravel(tree -> leftchild);
  if (tree -> rightchild) PrintPostTravel(tree -> rightchild);
  printf("%c", tree -> data);
}

inline void PrintPreTravel(BitTree tree)
{
  if (tree == NULL) return ;
  printf("%c", tree -> data);
  if (tree -> leftchild) PrintPreTravel(tree -> leftchild);
  if (tree -> rightchild) PrintPreTravel(tree -> rightchild);
}

signed main()
{
    char pre[20], in[20]; int n;
    TreeNode *tree;

    printf("输入先序序列\n输入中序序列\n后序序列：");
    scanf("%s %s", pre, in);
    n = 0;
    while (pre[n]) n ++;
    tree = CreateBitTree1(pre, in, 0, n - 1, 0, n - 1);
    PrintPostTravel(tree);
    printf("\n");

    printf("输入后序序列\n输入中序序列\n先序序列：");
    scanf("%s %s", pre, in);
    n = 0;
    while (pre[n]) n ++;
    tree = CreateBitTree2(pre, in, 0, n - 1, 0, n - 1);
    PrintPreTravel(tree);
    printf("\n");

    return 0;
}