CareerCup

struct node *head, *reverse, *second;
\\assign head to the head of the linked list
head = top; \\where top already points to the first node
reverse = second = null;
while(head != null){
second = head->next;
head->next = reverse;
reverse = head;
head = second;
}

struct node *head, *reverse, *second;
\\assign head to the head of the linked list
head = top; \\where top already points to the first node
reverse = second = null;
while(head != null){
second = head->next;
head->next = reverse;
reverse = head;
head = second;
}

struct node *head, *reverse, *second;
\\assign head to the head of the linked list
head = top; \\where top already points to the first node
reverse = second = null;
while(head != null){
second = head->next;
head->next = reverse;
reverse = head;
head = second;
}

struct node *head, *reverse, *second;
\\assign head to the head of the linked list
head = top; \\where top already points to the first node
reverse = second = null;
while(head != null){
second = head->next;
head->next = reverse;
reverse = head;
head = second;
}

Tested and working code, should take care of edge case tests.

Node MakeSingleLinkedListReverse(Node currentNode)
{
    Node previousNode = null;
    Node nextNode = null;
           
    while (currentNode != null)
    {
        nextNode = currentNode.NextNode;
        currentNode.NextNode = previousNode;

        previousNode = currentNode;
        currentNode = nextNode;
    }

    return previousNode;
}

typedef struct Node_tag
{
int value;
struct Node_tag* next;
} Node;

Node* ReverseLinkedList(Node* p)
{
Node* r = p;

if (p && p->next)
{
Node* pn = p->next;
p->next = NULL;

while(pn)
{
Node* pnn = pn->next;
pn->next = p;
p = pn;
pn = pnn;
}
}
return p;
}