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  1. #include <iostream>
  2. using namespace std;
  3.  
  4. class Node {
  5. public:
  6.     int data;
  7.     Node *next;
  8.  
  9.     Node(int data) : data(data), next(NULL) {}
  10. };
  11.  
  12. class LinkedList {
  13. private:
  14. 	Node *head, *tail;
  15.  
  16. public:
  17. 	LinkedList() : head(NULL), tail(NULL) {}
  18.  
  19. 	// disabling these just for demonstration purposes,
  20.     // but you really should implement them properly...
  21.     LinkedList(const LinkedList&) = delete;
  22.     LinkedList& operator=(const LinkedList&) = delete;
  23.     //
  24.  
  25. 	~LinkedList() {
  26. 		Node *p = head, *n;
  27. 		while (p) {
  28. 			n = p->next;
  29. 			delete p;
  30. 			p = n;
  31. 		}
  32. 	}
  33.  
  34. 	Node* add(int data) {
  35. 		Node *newNode = new Node(data);
  36.         if (!head) {
  37.             head = newNode;
  38.         }
  39. 		if (tail) {
  40.             tail->next = newNode;
  41.         }
  42. 		tail = newNode;
  43. 		return newNode;
  44. 	}
  45.  
  46. 	void print() const {
  47. 		Node *p = head;
  48. 		while (p) {
  49. 			cout << p->data << ' ';
  50. 			p = p->next;
  51. 		}
  52. 		cout << endl;
  53. 	}
  54.  
  55. 	void deleteAlternateNodes() {
  56. 		Node *p = head, *q;
  57. 		while ((p != NULL) && (p->next != NULL)) {
  58. 			q = p->next;
  59. 			p->next = q->next;
  60. 			if (tail == q) tail = p;
  61. 			delete q;
  62. 			p = p->next;
  63. 		}
  64. 	}
  65. };
  66.  
  67. int main() {
  68. 	LinkedList ll;
  69.  
  70. 	int data;
  71.     while ((cin >> data) && (data != -1)) {
  72.         ll.add(data);
  73.     }
  74.  
  75.     ll.print();
  76.     ll.deleteAlternateNodes();
  77.     ll.print();
  78.  
  79.     return 0;
  80. }
Success #stdin #stdout 0.01s 5660KB
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https://ideone.com/QV17ps
language:
C++ 4.3.2 (gcc-4.3.2)
created:
3 years ago
visibility:
public

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