Binary tree and its application--two fork tree create __ Two fork Tree

the data type of the given binary tree is as follows

typedef char Element;
struct Node
{
    Element data;
    struct Node *lchild;
    struct Node *rchild;
typedef struct NODE Btnode;
typedef struct NODE * BTREE;

Two fork tree creation I
Complete the Btree create_btree (char s[]) function, the function creates a binary tree from the string s, where the string s is represented by a generalized table of two-forked trees consisting only of ' (', ', ') ', ', ' and uppercase and lowercase characters, such as a (B (D,), C (E,f (, H) ), and the string s ends with ' i '.

Btree NewNode (Element x)
{
    btree p= (btree) malloc (sizeof (Btnode));
    p‐>data=x;
    p‐>lchild=null;
    p‐>rchild=null;
    return p;
}
Btree Create_btree (char s[])
{
    int i,k,top;
    Btree path[n],p;
    k=0;
    top=‐1;
    For (i=0;s[i]!= ' and i++ ')
    {
        switch (s[i))
        {case 
        ' (':
            path[++top]=p;
            k=1;
            break;
        Case ', ':
            k=2;
            break;
        Case ') ':
            top‐‐;
            break; 
        if (Isalpha (S[i]))
        {
            p=newnode (s[i]);
            if (k==1)
                path[top]‐>lchild=p;
            else if (k==2)
                path[top]‐>rchild=p;
        }
    } 
    return path[0];
}

two fork Tree Creation II
Complete the Btree create_btree (char s[],int left,int right) function, which creates a binary tree from the string s (from S[left to S[right]), where the string s is only ' (', ') ', ', ', ' and a generalized table representation of a two-forked tree of uppercase and lowercase characters, such as a (B (D,), C (E,f (, H)), and the string s ends with '.

int find (char s[],int left,int right)
{
    int k=0;
    int i;
    for (i=left;i<=right;i++)
    {
        if (s[i]== ', ' &&k==1] return
            i;
        if (s[i]== ')
            k++;
        else if (s[i]== ') ')
            k‐‐
    } 
    return to left;
}
Btree NewNode (Element x)
{
    btree p= (btree) malloc (sizeof (Btnode));
    p‐>data=x;
    p‐>lchild=null;
    p‐>rchild=null;
    return p;
}
Btree Create_btree (char s[],int left,int right)
{
    int mid;
    if (left>right) return
        NULL;
    Btree P=newnode (S[left]);
    Mid=find (s,left,right);
    P‐>lchild=create_btree (s,left+2,mid‐1);
    P‐>rchild=create_btree (s,mid+1,right‐1);
    return p;
}

two fork Tree Creation III
the first sequence traversal output of the two-fork tree is given (the empty node uses '. ') , please construct the two-fork tree and output the node of the binary tree in order of the sequence traversal.

Enter a description:
Line only by '. ' A string consisting of uppercase and lowercase characters that represents the forward traversal output of a binary tree, where '. ' Represents an empty node with a string length not exceeding 100.
Output Description:
Outputs the nodes of the binary tree in a single row in order of the sequence traversal, and the null node does not output.
Enter a sample column:
ABD ... C..
Output Sample columns:
Dbac

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <queue> #include <cctype
> Using namespace std;
#define N-ary typedef char Element;
    struct Node {Element data;
    struct Node *lchild;
struct Node *rchild;
};
typedef struct NODE Btnode;
typedef struct NODE * BTREE;
Btree Create_btree ();
Btree NewNode (Element x);
void Pre_order (btree root);
    int main () {btree root;
    Root=create_btree ();
    Pre_order (root);
    printf ("\ n");
return 0;
    } btree NewNode (Element x) {btree p= (btree) malloc (sizeof (Btnode));
    p‐>data=x;
    p‐>lchild=null;
    p‐>rchild=null;
return p;
    } btree Create_btree () {btree root;
    char c;
    C=getchar ();
        if (c== '. ')
    return NULL;
    Root=newnode (c);
    Root‐>lchild=create_btree ();
    Root‐>rchild=create_btree ();
return root;
        } void Pre_order (Btree root) {if (root!=null) {pre_order (root‐>lchild);
printf ("%c", root‐>data);        Pre_order (Root‐>rchild); }
}