Graphics and Linked List Under C++
1 - I Have Borland C++ Compiler (DOS) 3.0 , My Problem .. When i tried to load my graphic program, i've got error message in this compiler. althought i loaded this program under different system it works .. but under my compiler doesn't.
2 - I tried to do my Linked list and i done it .. my problem how can i do my SORTING PROGRAM under Linked List ...
2 - I tried to do my Linked list and i done it .. my problem how can i do my SORTING PROGRAM under Linked List ...
1 : ???
Each graphics subsystem is usually compiler & system dependent. Can you give some more
infos( e.g. on which 'different' system did it work)?
2:
I remember there are various methods to sort linked lists. I know a quite simple method, it isn't
the fastest i think ...
a) Assign all your linked list items some sort of hash value which is sort order dependent,
perhaps like this:
unsigned long buildHash(char *text)
{
unsigned long ulValue=0;
int nPos;
for(nPos=0;nPos<4;nPos++) {
if(text[nPos]==0) break;
ulValue |= ((unsigned char)text[nPos])<<((3-nPos
}
return ulValue;
}
// example: HELLO -> 0x48454c4c
Then define a struct which takes the linked list item and its hash value:
struct _helper {
linkedlistitem *item;
unsigned long hash;
};
Build an array so that each linked-list item is contained, and then you can use the qsort()
function of C( or the STL implementation).
Then you can either use a bubble sort on the linked-list items which have the same hash
value - or you can proceed like above, assign those items with the same hash value a new
array, where the hash value starts with the 4th character.
In the worst case (all items are identical), you'll get O(N*N), in the best case, where all
(first) hash values are different, you'll get O(N).
Each graphics subsystem is usually compiler & system dependent. Can you give some more
infos( e.g. on which 'different' system did it work)?
2:
I remember there are various methods to sort linked lists. I know a quite simple method, it isn't
the fastest i think ...
a) Assign all your linked list items some sort of hash value which is sort order dependent,
perhaps like this:
unsigned long buildHash(char *text)
{
unsigned long ulValue=0;
int nPos;
for(nPos=0;nPos<4;nPos++) {
if(text[nPos]==0) break;
ulValue |= ((unsigned char)text[nPos])<<((3-nPos
}
return ulValue;
}
// example: HELLO -> 0x48454c4c
Then define a struct which takes the linked list item and its hash value:
struct _helper {
linkedlistitem *item;
unsigned long hash;
};
Build an array so that each linked-list item is contained, and then you can use the qsort()
function of C( or the STL implementation).
Then you can either use a bubble sort on the linked-list items which have the same hash
value - or you can proceed like above, assign those items with the same hash value a new
array, where the hash value starts with the 4th character.
In the worst case (all items are identical), you'll get O(N*N), in the best case, where all
(first) hash values are different, you'll get O(N).
Bubble sort is the slowest algorithm possible. Don't use it ...
If you sort more than 1000 elements, even a Pentium II 400 goes down :)
If you sort more than 1000 elements, even a Pentium II 400 goes down :)
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