As Karl and John have already noted you need to do some
work yourself and provide the details.
However, as to the C _code_, why do you post C code in a
C++ group?
On 23 Jul 2003 01:02:20 -0700,
(Jeff Cheng) wrote:
>Can anybody help to trace the runtime error for the following code
>about sub-Linked list.
>
>Thank you,
>
>
># include <stdio.h>
That should be
#include <cstdio>
_if_ that header was required. But these facilities are not, in
general, type safe. So at your current level you should not use
them for anything -- use <iostream> instead.
># include <stdlib.h>
That should be
#include <cstdlib>
_if_ that header were required (which it isn't).
>typedef char *CategoryType;
>typedef char *ItemType;
>typedef char *CodeType;
Yes it is a good idea to name things. No it isn't a good
idea to represent these types as the same type. If they have
different functionality, e.g. restrictions on the set of
valid values, capture that by using proper classes.
Also, it's absolutely not a good idea to use char* even where
you only need a string of characters.
Use std::string instead, so as to avoid allocation and
deallocation bugs.
>typedef int QtyType;
Yes it is a good idea to name things. No it isn't a good
idea to hide the direct representation as int behind a
name. Use a class, or use plain int.
>typedef struct node_item {
> ItemType ItemDesc;
> CodeType CodeNo;
> QtyType Quantity;
> node_item *NextItemLink;
>} items;
In C++ that would be
struct node_item {
itemType ItemDesc;
CodeType CodeNo;
QtyType Quantity;
node_item *NextItemLink;
};
typedef node_item items;
But what is it you imagine that you need the typedef for?
It's _not_ a good idea to introduce aliases for type names.
>typedef struct node_cat {
> node_item *ItemLink;
> CategoryType CatData;
> node_cat *CatLink;
>} category;
Ditto.
>typedef category *CatPtr;
>//typedef items *ItemLink;
>typedef items *ItemLink;
>
>void Initialise (CatPtr *L) {
> *L = NULL;
>}
Use a constructor for initialization.
>// this is to add category
>void AddCatNode (CatPtr *L, CategoryType x) {
> CatPtr p, q;
>
> p=(CatPtr) malloc (sizeof(category));
Don't use malloc. In C++ use 'new'.
> p->CatData = x;
> p->CatLink = NULL;
> if (*L == NULL)
> *L = p;
> else {
> q = *L;
> while (q->CatLink!=NULL)
> q=q->CatLink;
> q->CatLink = p;
> }
> }
>
>// this is to add item
>void AddItemNode (ItemLink *L, ItemType x, CodeType y, QtyType z) {
> ItemLink p, q;
>
> p=(ItemLink) malloc (sizeof(items));
> p->ItemDesc = x;
> p->CodeNo = y;
> p->Quantity = z;
> p->NextItemLink = NULL;
> if (*L == NULL)
> *L = p;
> else {
> q = *L;
>
> //while (q->NextItemLink!=NULL)
> // q=q->NextItemLink;
> //q->NextItemLink = p;
> }
> }
Indentation, indentation, indentation.
>//cat search
>CatPtr SearchCatList (CatPtr L, CategoryType x) {
> CatPtr p;
> p = L;
> while (p!=NULL) {
> if (x == p->CatData)
> return p;
> else
> p=p->CatLink;
> }
> return p;
> }
>
>//item search
>ItemLink SearchItemList (ItemLink L, ItemType x) {
> ItemLink p;
> p = L;
> while (p!=NULL) {
> if (x == p->CodeNo)
> return p;
> else
> p=p->NextItemLink;
> }
> return p;
> }
>
>//item display
>void DisplayItemList (ItemLink L) {
> ItemLink p;
>
> for (p=L; p!=NULL; p=p->NextItemLink) {
> printf("%s\n", p->ItemDesc);
> printf("%s\n", p->CodeNo);
> printf("%d\n", p->Quantity);
> }
>}
>
>
>
>void main() {
Invalid in both C and C++. Should be
int main()
> CatPtr CatList,p;
> ItemLink ItemList, i;
> int choice, z;
> char yn;
> char *x, *y;
>
>
> Initialise (&CatList);
>
> do {
>
> printf ("Main Menu\n");
> printf ("1. Add Record\n");
> printf ("2. Search\n");
> printf ("3. Print\n");
> printf ("9. Exit\n");
> printf("\nPlease enter your choice> ");
> scanf ("%d", &choice);
>
> switch (choice) {
> case 1:
> printf ("Please select what you want to add\n");
> printf ("1. Add Category\n");
> printf ("2. Add Item\n");
> printf ("Please enter your choice> ");
> scanf ("%d", &choice);
>
> // this is to add new category
> if (choice == 1) {
> printf ("Please key in New Category> ");
> scanf ("%s", &x);
> AddCatNode (&CatList, x);
> }
>
> // this is to add new item
> if (choice == 2) {
> printf ("Please key in Category> ");
> scanf ("%s", &x);
> p= SearchCatList (CatList, x);
> if (p==NULL)
> printf ("Category not found\n");
> else {
> printf ("Please enter the New Item> ");
> scanf ("%s", &x);
> printf ("Please enter the New Code> ");
> scanf ("%s", &y);
> printf ("Please enter the Quantity> ");
> scanf ("%d", &z);
> AddItemNode (&ItemList, x, y ,z);
> }
> }
>
> break;
>
>
> case 2:
> printf ("Please Enter Category> ");
> scanf("%s", &x);
> p = SearchCatList (CatList, x);
>
> printf ("Please Enter Code No> ");
> scanf("%s", &y);
> i = SearchItemList (ItemList, y);
>
> if (i==NULL)
> printf ("No such item");
> else {
> printf("%s", i->ItemDesc);
> printf("%s", i->CodeNo);
> printf("%d", i->Quantity);
> }
> break;
>
> case 3:
> printf ("Please enter your Category> ");
> scanf ("%s", &x);
>
> DisplayItemList (ItemList);
> break;
>
>
> //int tem;
> //tem = 1;
> //while (tem < 100000) {
> // tem++;
> printf("%s", &x);
> //}
>
>
> }
> }while (choice !=9);
>
>}
The number of lines in main is unacceptable. Keep it down to
something that can be grokked at a glance.
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