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What is the value printed by the following C program ?
#include < stdio.h>
int f (int *a, int n)
{
if (n < = 0) return 0;
else if (*a% 2 = = 0) return *a + f(a + 1, n – 1);
else return *a – f(a + 1, n – 1);
}
int main ()
{
int a [] = {12, 7, 13, 4, 11, 6};
print f (“%d, f(a, 6));
return 0,
}
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- – 9
- 5
- 15
- 19
- – 9
Correct Option: C
f() is a recursive function which adds f(a + 1, n – 1) to *a if *a is even. If *a is odd then f() subtracts f(a + 1, n – 1) from *a. See below recursion tree for execution of f(a, 6).
f(add(12), 6) /*Since 12 is first element. a contains
address of 12 */
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12 + f(add(7), 5) /* Since 7 is the next element, a+1 contains address of 7 */
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7 – f(add(13), 4)
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13 – f(add(4), 3)
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4 + f(add(11), 2)
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11 – f(add(6), 1)
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6 + 0
So, the final returned value is
12 + (7 – (13 – (4 + (11 – (6 + 0))))) = 15
