Why is the output of the following C code 10 41 ?

Question

int main()
{
int e=5,f=0;
f=(++e) + (++e) + (++e) + (++e) + (++e);
printf("%d %d\n",e,f);
return 0;
}
It should be 10 40 but it's coming out to be 10 41.

Answer 1

Using ++ operator more times in single line is UNDEFINED. You never know what will come up, depends on compiler or compiler flags