Programming In C

Question

Question 

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?

• A    8, 4, 0, 2, 14
• B    8, 4, 0, 2, 0
• C    2, 0, 4, 8, 14
• D    2, 0, 4, 8, 0

Please give step by step explanation?

Comments

inside main() : 

printf (“%d/n”, sum);  

This will print $0$. options A and C eliminated

---

The first recursive call to return form stack is foo(0,sum) : this call prints nothing.

The next recursive call to return form stack is foo(2,sum) : here local variable k value is $2$ and for the first time  prints $2$

So, Option D is correct.

Answer 1

B is correct option.

1.main()

a=2048

sum =0

2.foo(2048,0)

n=2048

Sum=0

K= 8 j= 204

Sum= 8

3.foo(204,8)

n= 204 sum= 8

K=4 j=20

sum= 12

4.foo(20,12)

​​​​n=20 sum=12

K= 0 j= 2

Sum = 12

5.foo(2,12)

n=2 sum 12

K= 2 j=0

Sum =14

6.foo(0,14)

return to 5

In 5 print k =2 then return to 4

In 4 print k=0 then return to 3

In 3 print k = 4 then return to 2

In 2 print k =8 then return to 1. i-e main()

In main sum variable remains 0

As only value of sum variable was passed

Hence sum =0

Will be printed!