sum of last and first digit of a number using recursion function

[FoaaD2506]

HEllo. i wrote those functions which look like recursive functions but i'm not satisfied i feel like it's not recursive, is there a way to write only one recursive function to do both jobs? or two functions but in a "real" recursive way ?

#include <iostream>
using namespace std;

int first(int num)
{
   if (num<10)
   return num;
   else
   while (num>10)
   return first(num/10);
}
int last(int num)
{
    if(num<10)
    return num;
    else
    return last(num%10);
}

int main()
{
 int x;
 cin>>x;
 cout<<"sum is "<<first(x)+last(x)<<endl;
}

[lastchance]

In int first() you can simply remove lines 8 and 9.


You second function could be simplified to

int last(int num)
{
   return num%10;
}

but it's barely worth a function at all.

[Manga]

Your original program did not work if you put in numbers greater than 100.

#include <iostream>
using namespace std;

int first(int num)
{
   if (num<10)
   return num;
  
   first(num/10);
}


int main()
{
    
 int x;
 cin>>x;
 
 if(x>10) {
 cout<<"sum is "<< first(x) + x%10<<endl;
 }
 
else {
     cout<<"sum is "<< x <<endl;
}


return 0;
}

[FoaaD2506]

thank you first of all.
actually it worked for me with those two functions with any number i even entered 10 digits and it worked but i wanted a simple recursive function to do the job, my functions were more like a normal function.

[dutch]

#include <iostream>

int sum_first_and_last(unsigned long n, int top = 1)
{
    return n < 10 ? n : sum_first_and_last(n / 10, 0) + n % 10 * top;
}

int main()
{
    std::cout << sum_first_and_last(31234567890123456) << '\n';
}