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 6 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 6 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 6 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 6 mins ago
Error_loading
184
asked 6 mins ago
Error_loading
184
asked 6 mins ago
Error_loading
184
asked 6 mins ago
Error_loading
184
asked 6 mins ago
Error_loading
184
184
add a comment |
add a comment |
0
active
oldest
votes
Your Answer
StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["\$", "\$"]]);
});
});
}, "mathjax-editing");
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "196"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
draft saved
draft discarded
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f210792%2fpairwise-swap-elements-of-a-given-linked-list-by-changing-links%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
0
active
oldest
votes
0
active
oldest
votes
active
oldest
votes
active
oldest
votes
draft saved
draft discarded
Thanks for contributing an answer to Code Review Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
draft saved
draft discarded
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fcodereview.stackexchange.com%2fquestions%2f210792%2fpairwise-swap-elements-of-a-given-linked-list-by-changing-links%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
