GATE | GATE CS 2008 | Question 62
The following C function takes a single-linked list of integers as a parameter and rearranges the elements of the list. 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) || !list->next) return ; p = list; q = list->next; while (q) { temp = p->value; p->value = q->value; q->value = temp; p = q->next; q = p?p->next:0; } } |
(A) 1,2,3,4,5,6,7
(B) 2,1,4,3,6,5,7
(C) 1,3,2,5,4,7,6
(D) 2,3,4,5,6,7,1
Answer: (B)
Explanation:
Given linked list is 1->2->3->4->5->6->7
If you carefully observe the given function,
It just swaps the adjacent values for every pair till it reaches the end.
The modified linked list is 2->1->4->3->6->5->7
See Question 4 of https://www.geeksforgeeks.org/data-structures-and-algorithms-set-15/
This solution is contributed by Anil Saikrishna Devarasetty
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