Question

The following C function takes a singly-linked list of integers as a parameter and rearranges the elements of the list. The list is represented as pointer to a structure. The function is called with the list containing the integers 1, 2, 3, 4, 5, 6, 7 in the given order.

What will be the contents of the list after the function completes execution?

struct node
{
int value;
struct node *next;
};
void rearrange (struct node *list)
{
struct node *p, *q;
int temp;
if (!list $\mid$ $\mid$ !list $\to$ next)
return;
p = list;
q = list $\to$ next;
while (q)
{
temp = p $\to$ value;
p $\to$ value = q $\to$ value;
q $\to$ value = temp;
p = q$\to$ next;
q = p ? p $\to$ next : 0;
}
}

• A. 2, 1, 4, 3, 6, 5, 7
• B. 1, 2, 3, 4, 5, 6, 7
• C. 2, 3, 4, 5, 6, 7, 1
• D. 1, 3, 2, 5, 4, 7, 6

Answer 1

The correct option is A 2, 1, 4, 3, 6, 5, 7

2 1 4 3 6 5 7 : as p and q are swapping each other where q is
p$\to$ next all the time.