Algorithm - Search - Find the Median

Find the Median

The following is the solution to Hacker Rank problem Find the Median using Java.  For solutions to other Hacker Rank Problem visit my page HackerRank, alternatively try searching for the problem in my blog.

Score: 10/10

/**  *  */ import java.io.*; import java.util.*; import java.text.*; import java.math.*; import java.util.regex.*; /**  * @author Arun.G  *  */ public class Solution{        /**         * @param args         */        public static void main(String[] args) {               /*                * Enter your code here. Read input from STDIN. Print output to STDOUT.                * Your class should be named Solution.                */               Scanner sc = new Scanner(System.in);               int n = sc.nextInt();               int[] ar = new int[n];               for (int i = 0; i < n; i++) {                      ar[i] = sc.nextInt();               }               Arrays.sort(ar);               int median = ar[ar.length / 2];               System.out.println(median);               sc.close();        } }

Algorithm - Linked Lists - Insert a node at the tail of a linked list

Insert a node at the tail of a linked list

The following is the solution to Hacker Rank problem Insert a node at the tail of a linked list using Java.  For solutions to other Hacker Rank Problem visit my page HackerRank, alternatively try searching for the problem in my blog.

Score: 5/5

#include<iostream> #include<cstdio> #include<cstdlib> using namespace std; struct Node {                 int data;                 Node *next; };/*   Insert Node at the end of a linked list   head pointer input could be NULL as well for empty list   Node is defined as   struct Node   {      int data;      struct Node *next;   } */ Node* Insert(Node *head,int data) {   // Complete this method     Node *headPtr = new Node();     headPtr = head;     if(head!=NULL)     {         while(head->next!=NULL)         {             head = head->next;         }         Node *tail = new Node();          tail->data = data;         tail->next = NULL;         head->next = tail;                    }     else     {         Node *tail = new Node();          tail->data = data;         tail->next = NULL;         headPtr = tail;     }                 return headPtr; }void Print(Node *head) {                 Node *temp = head;                 while(temp!= NULL){ cout<<temp->data<<"\n";temp = temp->next;} } int main() {                 int t;                 cin>>t;                 Node *head = NULL;                 while(t-- >0)                 {                                 int x; cin>>x;                                 head = Insert(head,x);                 }                 Print(head); }

Algorithm - Linked Lists- Insert a node at the head of a linked list

Insert a node at the head of a linked list

The following is the solution to Hacker Rank problem  Insert a node at the head of a linked list using Java.  For solutions to other Hacker Rank Problem visit my page HackerRank, alternatively try searching for the problem in my blog.

Score: 5/5

#include <iostream> #include<cstdio> #include<cstdlib> using namespace std; struct Node {                 int data;                 Node *next; };/*   Insert Node at the begining of a linked list   Initially head pointer argument could be NULL for empty list   Node is defined as   struct Node   {      int data;      struct Node *next;   } return back the pointer to the head of the linked list in the below method. */ Node* Insert(Node *head,int data) {      Node *newHead = new Node();   // Complete this method     if(head!= NULL)     {              newHead->data = data;         newHead->next = head;     }     else     {              newHead->data = data;         newHead->next = NULL;     }     return newHead; }void Print(Node *head) {                 Node *temp = head;                 while(temp!= NULL){ cout<<temp->data<<"\n";temp = temp->next;} } int main() {                 int t;                 cin>>t;                 Node *head = NULL;                 while(t-- >0)                 {                                 int x; cin>>x;                                 head = Insert(head,x);                 }                 Print(head); }

Algorithm - Linked Lists- Print the elements of a linked list

Print the elements of a linked list

The following is the solution to Hacker Rank problem Print the elements of a linked list using Java.  For solutions to other Hacker Rank Problem visit my page HackerRank, alternatively try searching for the problem in my blog.

Score: 5/5

#include <iostream> #include <cstdio> #include <cstdlib> using namespace std; struct Node {                 int data;                 Node *next; };/*   Print elements of a linked list on console   head pointer input could be NULL as well for empty list   Node is defined as   struct Node   {      int data;      struct Node *next;   } */ void Print(Node *head) {   // This is a "method-only" submission.   // You only need to complete this method.      if(head != NULL)      {          std::cout<<head->data<<"\n";    if(head->next != NULL)         Print(head->next);      }     }Node* Insert(Node *head,int x) {    Node *temp = new Node();    temp->data = x;    temp->next = NULL;    if(head == NULL)    {        return temp;    }    Node *temp1;    for(temp1 = head;temp1->next!=NULL;temp1= temp1->next);    temp1->next = temp;return head; } int main() {                 int t;                 cin>>t;                 while(t-- >0)                 {                                                int x; cin>>x;                                  Node *head = NULL;                 while(x--)                 {                                                                                                       int y;cin>>y;                                            head = Insert(head,y);                 }                 Print(head);                                                 free(head);                 } }

Hacker Rank Problem - Algorithm - Search- Encryption

Encryption 

The following is the solution to Hacker Rank problem Encryption using Java.  For solutions to other Hacker Rank Problem visit my page HackerRank, alternatively try searching for the problem in my blog.

Score:25/25

/**  *  */ package hackerRank; import java.util.Scanner; /**  * @author Arun.G  *  */ public class Encryption {        /**         * @param args         */        public static void main(String[] args) {               // TODO Auto-generated method stub               Scanner sc = new Scanner(System.in);               String word = sc.nextLine();                             // Remove all white space characters               word = word.replaceAll("\\s+", "");                             //compute the width and height               int width = (int) Math.ceil(Math.sqrt(word.length()));               int height = (int) Math.floor(Math.sqrt(word.length()));                             int newHeight = 0, newWidth = 0;               //some times we can fit in the the word with given width find and increase the height               if (word.length() / height >= width)                      height += 1;               String result = "";               char[][] secret = null;               //find the correction width and height or not equal               int correction = Math.abs(width - height);                // if height is greater, correct the width and make it equal to height               if (height > width)               {                      secret = new char[height][width + correction];                      newWidth = width + correction;                      newHeight = height;               }               //if width is greater, correct the height and make it equal to width               else if (width > height)               {                      secret = new char[height + correction][width];                      newHeight = height + correction;                      newWidth = width;               }               //else height and width are equal               else               {                      secret = new char[height][width];                      newHeight = height;                      newWidth = width;               }                int index = 0;               //write down the message in the row major order in array               for (int i = 0; i < height; i++) {                      for (int j = 0; j < width; j++) {                            if (index + 1 <= word.length()) {                                   secret[i][j] = word.charAt(index);                                   index++;                            }                      }               }               //get the message from the array in column major order               for (int i = 0; i < newHeight; i++) {                      for (int j = 0; j < newWidth; j++) {                            //if the character is not null add it to result                            if ((secret[j][i] != '\0'))                                   result += Character.toString(secret[j][i]);                      }                      result += " ";               }               System.out.println(result);               sc.close();        } }

Hacker Rank Problem - Algorithm - Search- Flower

Flower

The following is the solution to Hacker Rank problem Flowers using Java.  For solutions to other Hacker Rank Problem visit my page HackerRank, alternatively try searching for the problem in my blog.

Score: 24/24

/**  *  */ package hackerRank; import java.util.Arrays; import java.util.Comparator; import java.util.Scanner; /**  * @author Arun.G  *  */ public class Flowers {        /**         * @param args         */        public static void main(String[] args) {               // TODO Auto-generated method stub               // helpers for input/output               Scanner in = new Scanner(System.in);               int N, K;               N = in.nextInt();               K = in.nextInt();               Integer C[] = new Integer[N];               int bought[] = new int[K];               for (int i = 0; i < N; i++) {                      C[i] = in.nextInt();               }               int result = 0;               //sort the array in descending order               Arrays.sort(C, new Comparator<Integer>() {                      @Override                      public int compare(Integer x, Integer y) {                            return y - x;                      }               });               int index = 0;               for (int i = 0; i < C.length; i++) {                      // reset if crossed boundry                      if (index >= bought.length)                      {                            index = 0;                      }                      result += ((bought[index] + 1) * C[i]);                      bought[index] += 1;                      index++;               }                             System.out.println(result);               in.close();        } }

Hacker Rank Problem - Algorithm - Regex - IP Address Validation

IP Address Validation

The following is the solution to Hacker Rank problem IP Address Validation using Java.  For solutions to other Hacker Rank Problem visit my page HackerRank, alternatively try searching for the problem in my blog.

Score: 10/10

/**  *  */ package hackerRank; import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; /**  * @author Arun.G  *  */ public class IPAddressValidation {        /**         * @param args         */        public static void main(String[] args) {               // TODO Auto-generated method stub             /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */         Scanner sc = new Scanner(System.in);         int n= sc.nextInt();         //Regex expression for Ipv4         String ip4Regex="^(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[0-9]{1,2})(\\.(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[0-9]{1,2})){3}$";         Pattern ip4Pattern = Pattern.compile(ip4Regex);         //Regex expression for Ipv6         String ip6Regex="^([0-9A-Fa-f]{1,4}:){7}[0-9A-Fa-f]{1,4}$";         Pattern ip6Pattern = Pattern.compile(ip6Regex);                     Matcher matcher;         for(int i=0;i<=n;i++)         {             String line = sc.nextLine();             if(!line.equals(""))             {                 matcher = ip4Pattern.matcher(line);                 //check if it is a Ipv4 Address                 if(matcher.matches())                     System.out.println("IPv4");                 else                 {                     matcher = ip6Pattern.matcher(line);                     //check if it is Ipv6 Address                     if(matcher.matches())                         System.out.println("IPv6");                     else //else it is neither                         System.out.println("Neither");                 }             }         }         //close the scanner         sc.close();        } }