Reverse Linked List

• Time : O(n)
• Space : O(1)

using namespace std;

class LinkedList {
public:
  int value;
  LinkedList *next;

  LinkedList(int value) {
    this->value = value;
    this->next = nullptr;
  }
};

LinkedList *reverseLinkedList(LinkedList *head) {
  LinkedList* dummy = new LinkedList(-1);
	LinkedList* tmp;
	
	while(head) {
		tmp = head->next;
		head->next = dummy->next;
		dummy->next = head;
		head = tmp;
	}
	
  return dummy->next;
}