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  1. #include <iostream>
  2. using namespace std;
  3. struct node{
  4. 	         int data;
  5. 	         struct node* next;
  6. };
  7. struct node* createnode(int val)
  8. {
  9. 	struct node* p=(struct node*)malloc(sizeof(struct node));
  10. 	p->data=val;
  11. 	p->next=NULL;
  12. 	return p;
  13.  
  14. }
  15. struct node* evenreverse(struct node* head)
  16. {
  17. 	struct node* head1=NULL;
  18. 	struct node* tail1=NULL;
  19. 	struct node* temp=head;
  20. 	if(head==NULL || head->next==NULL|| head->next->next==NULL)
  21. 	return head;
  22. 	while(temp && temp->next)
  23. 	{
  24. 		if(head1==NULL)
  25. 		{
  26. 			head1=tail1=temp->next;
  27. 		}
  28. 		else
  29. 		{
  30. 			tail1->next=temp->next;
  31. 			tail1=tail1->next;
  32. 		}
  33. 		temp->next=temp->next->next;
  34. 		temp=temp->next;
  35. 	}
  36. 	tail1->next=NULL;
  37. 	struct node* cur=head1;
  38. 	struct node* next=NULL;
  39. 	struct node* prev=NULL;
  40.  
  41. 	while(cur)
  42. 	{
  43. 		next=cur->next;
  44. 		cur->next=prev;
  45. 		prev=cur;
  46. 		cur=next;
  47. 	}
  48. 	struct node* second=prev;
  49. 	struct node* first=head;
  50. 	while(first)
  51. 	{
  52. 		temp=second->next;
  53. 		second->next=first->next;
  54. 		first->next=second;
  55. 		second=temp;
  56. 		first=first->next->next;
  57. 	}
  58. return head;	
  59. }
  60. void printlinked(struct node* head)
  61. {
  62. 	while(head!=NULL)
  63. 	{
  64. 		cout<<head->data<<" ";
  65. 		head=head->next;
  66. 	}
  67. }
  68.  
  69. int main() {
  70. 	struct node* head=createnode(1);
  71. 	head->next=createnode(2);
  72. 	head->next->next=createnode(3);
  73. 	head->next->next->next=createnode(4);
  74.     head->next->next->next->next=createnode(5);
  75. 	head->next->next->next->next->next=createnode(6);
  76. 	head=evenreverse(head);
  77. 	printlinked(head);
  78. 	return 0;
  79. }
Success #stdin #stdout 0s 5288KB
comments (?)
stdin 
Standard input is empty
stdout 
1 6 3 4 5 2
https://ideone.com/qDefAI
language:
C++ (gcc 8.3)
created:
279 days ago
visibility:
public

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