Consider the following C function:

int f(int n)
{
   static int r = 0;
   if(n <= 0) return 1;
   if(n>3)
   {
     r = n;
     return f(n-2)+2;
   }
  return f(n-1)+r;
}

What is the value of f(5)?

Consider the following C program:

void foo (int n, int sum) {
  int k = 0, j = 0;
  if(n==0) return;
  k=n%10; j = n /10;
  sum = sum + k;
  foo(j, sum);
  printf("%d",k);
}
int main () {
  int a = 2048, sum = 0;
  foo(a, sum);
  printf("%d\n", sum);
}

What does the above program print?

Consider the following C program:

double foo(double); /* Line 1 */
int main () {
  double da, db;
  //input da
  db = foo(da);
}
double foo(double a){
  return a;
}

The above code compiled without any error or warning. If Line 1 is deleted, the above code will show:

Consider the following C function:

int f(int n)
{
static int i = 1;
if(n>=5) return n;
n = n+1;
i++;
return f(n);
}

The value returned by f(1) is