All Combinations of the alphabet

[jrlambs]

OK, so I'm trying to write some C++ code that will generate all combinations, of any size of the letters of the alphabet. so...

A
AB
AC
AD
AE

etc etc etc. the code I have now get a good amount of the combinations, but only keeps the combinations in oreder. ex: it gets ABE but not ACE, it gets CDF, but not CEF. here's what I have so far:

void main()
{
const int NUMITEMS = 26;
char items[100] = "";
for(int w=0; w< NUMITEMS; w++)
{
items[w] = (char)(start+w);
}
items[NUMITEMS] = '\0';
int num =0;
char temp[26];
for(int startPlace=0; startPlace<NUMITEMS; startPlace++)
{
for(int length=1; length<NUMITEMS-(startPlace-1); length++)
{
for(int last=startPlace+length-1; last<NUMITEMS; last++)
{
if(length == 1)
{
temp[0] = items[startPlace];
temp[1] = '\0';
last = NUMITEMS+1;
}
else
{

int i=0;
while(i<length-1)
{
temp[i] = items[startPlace+i];
i++;
}
temp[length-1] = items[last];
temp[length] = '\0';
}
//Code to calculate the best answer.


cout << temp<< "\n";
}
}
}
}

can anyone tweak my solution to help me get all of them or give come up with some code that will get them all?

PS: I'm looking for combinations, not permitations. Order Doesn't matter.

Thanks!

Jeff