Pairwise swap elements of a given linked list by changing links
0
Given a singly linked list, write a function to swap nodes pairwise.
For example :
**
if the linked list is 1->2->3->4->5->6->7 then the function should
change it to 2->1->4->3->6->5->7, and if the linked list is
1->2->3->4->5->6 then the function should change it to
2->1->4->3->6->5
link to the above question
**
#include <iostream>
// structure of a Node in the linked list
struct Node {
int data;
Node *next;
};
// append data to end of linked list
Node *append(Node *head, int data) {
auto newNode = new Node{data, nullptr};
if (head == nullptr)
return newNode;
auto temp{head};
while (temp->next)
temp = temp->next;
temp->next = newNode;
return head;
}
// display the list
void display(Node *head) {
std::cout << "The list : t";
while (head != nullptr) {
std::cout << head->data << " ";
head = head->next;
}
std::cout << std::endl ;
}
// pairwise swap of the elements in the given linked lists
void pairwiseSwap(Node **head_ref) {
if(((*head_ref) == nullptr) || ((*head_ref)->next == nullptr))
return ;
Node *temp1 = nullptr, *temp2 = nullptr ;
Node *prev = nullptr, *curr =(*head_ref) ;
while(curr != nullptr) {
// temp1 : first element of the pair
// temp2 : second element of the pair
temp1 = curr;
temp2 = curr->next;
// if the the 2nd element in the pair is nullptr, then exit the loop
if(temp2 == nullptr){
break ;
}
// curr = curr->next->next ;
// if the current element is head, then previous one must be nullptr
// In either case swapping the nodes
if(prev == nullptr){
prev = temp1;
temp1->next = temp2->next;
temp2->next = temp1;
(*head_ref) = temp2 ;
}
else {
temp1->next = temp2->next;
temp2->next = temp1;
prev->next = temp2;
prev = temp1;
}
// moving to the next pair of nodes
curr = temp1->next ;
}
}
// Driver function
int main() {
Node *a = nullptr ;
// for odd number of nodes
a = append(a, 15);
a = append(a, 10);
a = append(a, 5);
a = append(a, 20);
a = append(a, 3);
// a = append(a, 2);
pairwiseSwap(&a);
display(a);
// for even number of nodes
a = append(a, 15);
a = append(a, 10);
a = append(a, 5);
a = append(a, 20);
a = append(a, 3);
a = append(a, 2);
pairwiseSwap(&a);
display(a);
}
c++11 linked-list
asked 3 mins ago
Error_loading
184
add a comment |
0
Given a singly linked list, write a function to swap nodes pairwise.
For example :
**
if the linked list is 1->2->3->4->5->6->7 then the function should
change it to 2->1->4->3->6->5->7, and if the linked list is
1->2->3->4->5->6 then the function should change it to
2->1->4->3->6->5
link to the above question
**
#include <iostream>
// structure of a Node in the linked list
struct Node {
int data;
Node *next;
};
// append data to end of linked list
Node *append(Node *head, int data) {
auto newNode = new Node{data, nullptr};
if (head == nullptr)
return newNode;
auto temp{head};
while (temp->next)
temp = temp->next;
temp->next = newNode;
return head;
}
// display the list
void display(Node *head) {
std::cout << "The list : t";
while (head != nullptr) {
std::cout << head->data << " ";
head = head->next;
}
std::cout << std::endl ;
}
// pairwise swap of the elements in the given linked lists
void pairwiseSwap(Node **head_ref) {
if(((*head_ref) == nullptr) || ((*head_ref)->next == nullptr))
return ;
Node *temp1 = nullptr, *temp2 = nullptr ;
Node *prev = nullptr, *curr =(*head_ref) ;
while(curr != nullptr) {
// temp1 : first element of the pair
// temp2 : second element of the pair
temp1 = curr;
temp2 = curr->next;
// if the the 2nd element in the pair is nullptr, then exit the loop
if(temp2 == nullptr){
break ;
}
// curr = curr->next->next ;
// if the current element is head, then previous one must be nullptr
// In either case swapping the nodes
if(prev == nullptr){
prev = temp1;
temp1->next = temp2->next;
temp2->next = temp1;
(*head_ref) = temp2 ;
}
else {
temp1->next = temp2->next;
temp2->next = temp1;
prev->next = temp2;
prev = temp1;
}
// moving to the next pair of nodes
curr = temp1->next ;
}
}
// Driver function
int main() {
Node *a = nullptr ;
// for odd number of nodes
a = append(a, 15);
a = append(a, 10);
a = append(a, 5);
a = append(a, 20);
a = append(a, 3);
// a = append(a, 2);
pairwiseSwap(&a);
display(a);
// for even number of nodes
a = append(a, 15);
a = append(a, 10);
a = append(a, 5);
a = append(a, 20);
a = append(a, 3);
a = append(a, 2);
pairwiseSwap(&a);
display(a);
}
c++11 linked-list
asked 3 mins ago
Error_loading
184
add a comment |
0
0
0
Given a singly linked list, write a function to swap nodes pairwise.
For example :
**
if the linked list is 1->2->3->4->5->6->7 then the function should
change it to 2->1->4->3->6->5->7, and if the linked list is
1->2->3->4->5->6 then the function should change it to
2->1->4->3->6->5
link to the above question
**
#include <iostream>
// structure of a Node in the linked list
struct Node {
int data;
Node *next;
};
// append data to end of linked list
Node *append(Node *head, int data) {
auto newNode = new Node{data, nullptr};
if (head == nullptr)
return newNode;
auto temp{head};
while (temp->next)
temp = temp->next;
temp->next = newNode;
return head;
}
// display the list
void display(Node *head) {
std::cout << "The list : t";
while (head != nullptr) {
std::cout << head->data << " ";
head = head->next;
}
std::cout << std::endl ;
}
// pairwise swap of the elements in the given linked lists
void pairwiseSwap(Node **head_ref) {
if(((*head_ref) == nullptr) || ((*head_ref)->next == nullptr))
return ;
Node *temp1 = nullptr, *temp2 = nullptr ;
Node *prev = nullptr, *curr =(*head_ref) ;
while(curr != nullptr) {
// temp1 : first element of the pair
// temp2 : second element of the pair
temp1 = curr;
temp2 = curr->next;
// if the the 2nd element in the pair is nullptr, then exit the loop
if(temp2 == nullptr){
break ;
}
// curr = curr->next->next ;
// if the current element is head, then previous one must be nullptr
// In either case swapping the nodes
if(prev == nullptr){
prev = temp1;
temp1->next = temp2->next;
temp2->next = temp1;
(*head_ref) = temp2 ;
}
else {
temp1->next = temp2->next;
temp2->next = temp1;
prev->next = temp2;
prev = temp1;
}
// moving to the next pair of nodes
curr = temp1->next ;
}
}
// Driver function
int main() {
Node *a = nullptr ;
// for odd number of nodes
a = append(a, 15);
a = append(a, 10);
a = append(a, 5);
a = append(a, 20);
a = append(a, 3);
// a = append(a, 2);
pairwiseSwap(&a);
display(a);
// for even number of nodes
a = append(a, 15);
a = append(a, 10);
a = append(a, 5);
a = append(a, 20);
a = append(a, 3);
a = append(a, 2);
pairwiseSwap(&a);
display(a);
}
c++11 linked-list
asked 3 mins ago
Error_loading
184
Given a singly linked list, write a function to swap nodes pairwise.
For example :
**
if the linked list is 1->2->3->4->5->6->7 then the function should
change it to 2->1->4->3->6->5->7, and if the linked list is
1->2->3->4->5->6 then the function should change it to
2->1->4->3->6->5
link to the above question
**
#include <iostream>
// structure of a Node in the linked list
struct Node {
int data;
Node *next;
};
// append data to end of linked list
Node *append(Node *head, int data) {
auto newNode = new Node{data, nullptr};
if (head == nullptr)
return newNode;
auto temp{head};
while (temp->next)
temp = temp->next;
temp->next = newNode;
return head;
}
// display the list
void display(Node *head) {
std::cout << "The list : t";
while (head != nullptr) {
std::cout << head->data << " ";
head = head->next;
}
std::cout << std::endl ;
}
// pairwise swap of the elements in the given linked lists
void pairwiseSwap(Node **head_ref) {
if(((*head_ref) == nullptr) || ((*head_ref)->next == nullptr))
return ;
Node *temp1 = nullptr, *temp2 = nullptr ;
Node *prev = nullptr, *curr =(*head_ref) ;
while(curr != nullptr) {
// temp1 : first element of the pair
// temp2 : second element of the pair
temp1 = curr;
temp2 = curr->next;
// if the the 2nd element in the pair is nullptr, then exit the loop
if(temp2 == nullptr){
break ;
}
// curr = curr->next->next ;
// if the current element is head, then previous one must be nullptr
// In either case swapping the nodes
if(prev == nullptr){
prev = temp1;
temp1->next = temp2->next;
temp2->next = temp1;
(*head_ref) = temp2 ;
}
else {
temp1->next = temp2->next;
temp2->next = temp1;
prev->next = temp2;
prev = temp1;
}
// moving to the next pair of nodes
curr = temp1->next ;
}
}
// Driver function
int main() {
Node *a = nullptr ;
// for odd number of nodes
a = append(a, 15);
a = append(a, 10);
a = append(a, 5);
a = append(a, 20);
a = append(a, 3);
// a = append(a, 2);
pairwiseSwap(&a);
display(a);
// for even number of nodes
a = append(a, 15);
a = append(a, 10);
a = append(a, 5);
a = append(a, 20);
a = append(a, 3);
a = append(a, 2);
pairwiseSwap(&a);
display(a);
}
c++11 linked-list
c++11 linked-list
asked 3 mins ago
Error_loading
184
asked 3 mins ago
Error_loading
184
asked 3 mins ago
Error_loading
184
asked 3 mins ago
Error_loading
184
asked 3 mins ago
Error_loading
184
184
add a comment |
add a comment |
0
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