Algorithm
Problem Name: 30 days of code -
Objective
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Task
A Node class is provided for you in the editor. A Node object has an integer data field, data, and a Node instance pointer, next , pointing to another node (i.e.: the next node in a list). A removeDuplicates function is declared in your editor, which takes a pointer to the head node of a linked list as a parameter. Complete removeDuplicates so that it deletes any duplicate nodes from the list and returns the head of the updated list.
Note: The head pointer may be null, indicating that the list is empty. Be sure to reset your next pointer when performing deletions to avoid breaking the list.
Input Format
You do not need to read any input from stdin. The following input is handled by the locked stub code and passed to the removeDuplicates function:
The first line contains an integer, N, the number of nodes to be inserted.
The N subsequent lines each contain an integer describing the
value of a node being inserted at the list's tail.
Constraints
- The data elements of the linked list argument will always be in non-decreasing order.
Output Format
Your removeDuplicates function should return the head of the updated linked list. The locked stub code in your editor will print the returned list to stdout.
Sample Input
6
1
2
2
3
3
4
Sample Output
1 2 3 4 Code Examples
#1 Code Example with C Programming
Code -
C Programming
#include <math.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <limits.h>
#include <stdbool.h>
typedef struct Node
{
int data;
struct Node* next;
}Node;
Node* removeDuplicates(Node *head){
if (!head)
return head;
Node *node = head;
while (node->next) {
if (node->data == node->next->data)
node->next = node->next->next;
else
node = node->next;
}
return head;
}
Node* insert(Node *head,int data)
{
Node *p = (Node*)malloc(sizeof(Node));
p->data = data;
p->next=NULL;
if(head==NULL){
head=p;
}
else if(head->next==NULL)
{
head->next=p;
}
else{
Node *start=head;
while(start->next!=NULL)
start=start->next;
start->next=p;
}
return head;
}
void display(Node *head)
{
Node *start=head;
while(start)
{
printf("%d ",start->data);
start=start->next;
}
}
int main()
{
int T,data;
scanf("%d",&T);
Node *head=NULL;
while(T-->0){
scanf("%d",&data);
head=insert(head,data);
}
head=removeDuplicates(head);
display(head);
}
#2 Code Example with C++ Programming
Code -
C++ Programming
#include <cmath>
#include <iostream>
using namespace std;
class Node {
public:
int data;
Node *next;
Node(int d) {
data = d;
next = NULL;
}
};
class Solution {
public:
Node *removeDuplicates(Node *head) {
Node *curr = head;
while (curr && curr->next) {
while (curr->next && curr->data == curr->next->data) {
curr->next = curr->next->next;
}
curr = curr->next;
}
return head;
}
Node *insert(Node *head, int data) {
Node *p = new Node(data);
if (head == NULL) {
head = p;
} else if (head->next == NULL) {
head->next = p;
} else {
Node *start = head;
while (start->next != NULL) {
start = start->next;
}
start->next = p;
}
return head;
}
void display(Node *head) {
Node *start = head;
while (start) {
cout << start->data << " ";
start = start->next;
}
}
};
int main() {
Node *head = NULL;
Solution mylist;
int T, data;
cin >> T;
while (T-- > 0) {
cin >> data;
head = mylist.insert(head, data);
}
head = mylist.removeDuplicates(head);
mylist.display(head);
}
#3 Code Example with C# Programming
Code -
C# Programming
using System;
using System.Collections.Generic;
class Node
{
public int data;
public Node next;
public Node(int d){
data=d;
next=null;
}
}
class Solution {
public static Node removeDuplicates(Node head){
//Write your code here
var curr = head;
while (curr != null && curr.next != null)
{
while (curr.next != null && curr.data == curr.next.data)
{
curr.next = curr.next.next;
}
curr = curr.next;
}
return head;
}
public static Node insert(Node head,int data)
{
Node p=new Node(data);
if(head==null)
head=p;
else if(head.next==null)
head.next=p;
else
{
Node start=head;
while(start.next!=null)
start=start.next;
start.next=p;
}
return head;
}
public static void display(Node head)
{
Node start=head;
while(start!=null)
{
Console.Write(start.data+" ");
start=start.next;
}
}
static void Main(String[] args) {
Node head=null;
int T=Int32.Parse(Console.ReadLine());
while(T-->0){
int data=Int32.Parse(Console.ReadLine());
head=insert(head,data);
}
head=removeDuplicates(head);
display(head);
}
}
#4 Code Example with Java Programming
Code -
Java Programming
import java.util.Scanner;
class Node {
int data;
Node next;
Node(int d) {
data = d;
next = null;
}
}
class Solution {
public static Node removeDuplicates(Node head) {
Node curr = head;
while (curr != null && curr.next != null) {
while (curr.next != null && curr.data == curr.next.data) {
curr.next = curr.next.next;
}
curr = curr.next;
}
return head;
}
public static Node insert(Node head, int data) {
Node p = new Node(data);
if (head == null)
head = p;
else if (head.next == null)
head.next = p;
else {
Node start = head;
while (start.next != null)
start = start.next;
start.next = p;
}
return head;
}
public static void display(Node head) {
Node start = head;
while (start != null) {
System.out.print(start.data + " ");
start = start.next;
}
}
public static void main(String args[]) {
Scanner sc = new Scanner(System.in);
Node head = null;
int T = sc.nextInt();
while (T-- > 0) {
int ele = sc.nextInt();
head = insert(head, ele);
}
head = removeDuplicates(head);
display(head);
}
}
#5 Code Example with Javascript Programming
Code -
Javascript Programming
process.stdin.resume();
process.stdin.setEncoding('ascii');
var input_stdin = "";
var input_stdin_array = "";
var input_currentline = 0;
process.stdin.on('data', function (data) {
input_stdin += data;
});
process.stdin.on('end', function () {
input_stdin_array = input_stdin.split("\n");
main();
});
function readLine() {
return input_stdin_array[input_currentline++];
}
function Node(data){
this.data=data;
this.next=null;
}
function Solution(){
this.removeDuplicates=function(head){
//Write your code here
let current = head;
if (!current) return;
while (current.next) {
if (current.data === current.next.data) {
current.next = current.next.next
} else {
current = current.next
}
}
return head;
}
this.insert=function(head,data){
var p=new Node(data);
if(head==null){
head=p;
}
else if(head.next==null){
head.next=p;
}
else{
var start=head;
while(start.next!=null){
start=start.next;
}
start.next=p;
}
return head;
};
this.display=function(head){
var start=head;
while(start){
process.stdout.write(start.data+" ");
start=start.next;
}
};
}
function main(){
var T=parseInt(readLine());
var head=null;
var mylist=new Solution();
for(i = 0; i < T; i++){
var data=parseInt(readLine());
head=mylist.insert(head,data);
}
head=mylist.removeDuplicates(head);
mylist.display(head>;
}
#6 Code Example with Python Programming
Code -
Python Programming
class Node:
def __init__(self,data):
self.data = data
self.next = None
class Solution:
def insert(self,head,data):
p = Node(data)
if head==None:
head=p
elif head.next==None:
head.next=p
else:
start=head
while(start.next!=None):
start=start.next
start.next=p
return head
def display(self,head):
current = head
while current:
print(current.data,end=' ')
current = current.next
def removeDuplicates(self,head):
#Write your code here
curr = head
while curr is not None and curr.next is not None:
while curr.next is not None and curr.data is curr.next.data:
curr.next = curr.next.next
curr = curr.next
return head
mylist= Solution()
T=int(input())
head=None
for i in range(T):
data=int(input())
head=mylist.insert(head,data)
head=mylist.removeDuplicates(head)
mylist.display(head);
#7 Code Example with PHP Programming
Code -
PHP Programming
data = $d;
$this->next = NULL;
}
}
class Solution{
function removeDuplicates($head){
//Write your code here
$currentNode = $head;
while ($currentNode != null && $currentNode->next != null) {
$node = $currentNode;
while ($node->next != null) {
if ($node->next->data === $currentNode->data) {
$next = $node->next->next;
$node->next = $next;
} else {
$node = $node->next;
}
}
$currentNode = $currentNode->next;
}
return $head;
}
function insert($head,$data){
//complete this method
$p=new Node($data);
if($head==null){
$head=$p;
}
else if($head->next==null){
$head->next=$p;
}
else{
$start=$head;
while($start->next!=null){
$start=$start->next;
}
$start->next=$p;
}
return $head;
}
function display($head){
$start=$head;
while($start){
echo $start->data,' ';
$start=$start->next;
}
}
}
$T=intval(fgets(STDIN));
$head=null;
$mylist=new Solution();
while($T-->0){
$data=intval(fgets(STDIN));
$head=$mylist->insert($head,$data);
}
$head=$mylist->removeDuplicates($head);
$mylist->display($head);
?>