unidentified problem with stl

[agajantorayev]

I got the following code:

#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
using namespace std;

//checks whether the given string palindrome or not
bool is_palindrome(const string& str)
{
     return equal(str.begin(), str.end(), str.rbegin());    
}

//converts decimal integer to base B
char nums[]={"0123456789ABCDEFGHIJ"};

string to_base(int b, int num)
{
       int n=num, q, r;
       string nbase;
       while(q!=0){
                   q=n/b; r=n%b;
                   nbase.push_back(nums[r]);
                   n=q;
                   }
       reverse(nbase.begin(), nbase.end());
       return nbase;
}
int main()
{
    if(is_palindrome(to_base(10, 2*2))) cout<<to_base(10, 2);
    getchar();
}

th problem is:

if(is_palindrome(to_base(10, 2*2))) cout<<to_base(10, 2);

program does not print output 4;

but if only use the
cout<<to_base(10, 2);
it prints 4;
or if I use
if(is_palindrome(to_base(10, 2*2))) cout<<"PALINDROME";
it prints to stndrt output

PALINDROME

CAN ANYONE EXPLAIN ME WHY IT DOES NOT WORK? WHERE IS MY BUG? TO THOSE WHO FIND MY BUG BIG THANKS!!!

[kbw]

You're missing #include <string>

Also, q in to_base is uninitialised, making while(q!=0) non-deterministic.

[agajantorayev]

THANKS kbw VERY VERY VERY MUCH! for q!!!!!!!!!!!!