Need help (inorder-preorder-postorder)

[mnf7]

My program doesn't work properly. Please help me

#include "stdafx.h"
#include <iostream>
#include <conio.h>
#include <stdio.h>
#include <string.h>
using namespace std;
 
class node{
    public:
        node *child_left;
        node *child_right;
        char value [11];
};
node *reshe = NULL;    
//#######################################################
void insert (node *c)
{
    node *a;
    node *b;
    b = NULL;
    a = reshe;
 
    while ( a!=NULL)
{
    b = a;
    if(strcmp(c->value,a->value) < 0)
{
    a= a-> child_left; 
}
    else
{
    a= a-> child_right; 
}
}
    if( b==NULL )
{
    reshe=c;
}
    else if(strcmp( c->value,b->value) < 0)
{
    b -> child_left = c;
}
    else
{
    b-> child_right = c;
}
}
//#######################################################
void preorder(node *r){
    if( r!=NULL)
    {
        cout<<"   "<< r->value;
        preorder(r->child_left);
        preorder(r->child_right);
    } 
}
//#######################################################
void inorder(node* r){
    if( r!=NULL)
    {
        inorder(r->child_left);
        cout << r->value << " " ;
        inorder(r->child_right);
    }
}
//########################################################
void postorder(node* r){
    if( r!=NULL)
    {
        inorder(r->child_left);
        inorder(r->child_right);
        cout << r->value << " " ;
 
    }
}
//#######################################################
void main()
{
    int choice=0 ;
    while (choice!=3){
    system("cls");
    cout<<"\n\n\t 1. Insert a Expression.";
    cout<<"\n\n\t 2. peymayesh.";
    cout<<"\n\n\t 3. Exit.";
    cout<<"\n\n\t Enter your choice : ";
    cin>>choice;
 
    switch (choice)
{
    case 1:{ system("cls");
            node *c=new node;
            cout<<"\n\n\t Enter your Expression Trees: ";
            cin >> c->value;
            c->child_right=NULL; 
            c->child_left=NULL; 
            insert(c); 
           }
            break;
    case 2:{ system("cls");
            cout << "\n\n\t  peymayesh Preorder : ";
            preorder(reshe);
            cout << "\n\n\t  peymayesh Inorder : ";
            inorder(reshe);
            cout << "\n\n\t  peymayesh Postorder : ";
            postorder(reshe);
            getchar();
            getchar();
           }
            break;
    case 3: break;
}
}
}

[weaknessforcats]

There are too many bugs in the code to address here. I suggest you step through the code using your debugger.

The obvious bugs are:
1) in the insert function the argument is a node* c. However, c is not used in the search while loop. What is used is a node* a that has never been initialized.

2)In the inorder, preorder, and postorder functions a recursive call is made if the argument node* is not NULL. However, if it is NULL, the functions just quit without doing anything.