Hexavigesimal Conversion (Base 10 to Base 26)

Convert a Base 10 number to a Base 26 equivalent

 #include <iostream>

using namespace std;
void base26(int num){
string hex = "";
int ret = 0;
while ( num > 25 ){
int i = num % 26;
num = num / 26;
ret = atoi(hex.c_str());
hex = (char)(i+97)+ret;
}
hex = (char)(num+97) + ret;
for ( int i = 0; i < hex.size(); i++ )
cout << hex[i];
}
int main(){
int num;
cout << "Enter base 10(1-25) number to convert to base 26 (Hexavigesimal):\n";
cin >> num;
if ( num > 25 ){
cout << "Error must be 1-25\n"; exit(1);
}//endif
base26(num);
return 0;
}