std::list question: copy, sort and Merge....

ArthurHuang · 06-24-2011, 03:39 PM

Hi, I had a data structure like this:

typedef struct node
{
int id;
int grade;
string name;
}

....
list<node> *node_list1, *node_list2, *node_list3;
....

I sort the list like this:
bool compareID(node *n1, node *n2)
{
return true?n1->id>n2->id:false;
}
node_list1.sort(compareID);
I think the logic is correct, maybe just some details.
Now my question is
1) Can I simply merge node1 and 2 without sorting?
Like node_list1.merge(node_list2);
2) If not, how can I copy list1 and 2 into list3?

thanks!

graemef · 06-26-2011, 10:18 AM

the compareID function is a trifle odd. Typically the ?: operator is as follows

Code:

condition ? value if true : value if false

Thus the condition will always be true

It's not possible to give a reasonable answer to your question without knowing how you want the lists to be stored. Should they be sorted after the merge? Are the already sorted before?

If they are sorted before and you want them to be sorted after then look up the details of merge sort (google can help).