Question: I get this error when I try to compile my program. It has to do with the way I'm constructing the map, but I really can't see something wrong:

```
error: expected identifier before numeric constant 
map <int , vector <int> >  radixM (10 , vector <int> (100));

```

Any ideas?

Answer: 
Store the results of each thread in a stack. One thread collects results from every thread and adds them together. Of course the stack should not be empty.

If you want multiple threads to work on factorials why not create a thread or two that produce a list of factorial results. Other threads can just look up results if needed.
Instead of having the same shared memory, you can have multiple threads with individual memories in a stack. Eventually, add all these up together (or occasionally) with one thread!