Program to Find the Maximum and Minimum Value Node From a Doubly Linked List

Q. Program to find the maximum and minimum value node from a doubly linked list.

Explanation

In this program, we will create a doubly linked list then, iterate through the list to find out the minimum and maximum node.

Program to find the maximum and minimum value node from a doubly linked list

We will maintain two variables min and max. Min will hold the minimum value node, and max will hold the maximum value node. In above example, 1 will be the minimum value node and 9 will be the maximum value node.

Algorithm

Define a Node class which represents a node in the list. It will have three properties: data, previous which will point to the previous node and next which will point to the next node.
Define another class for creating the doubly linked list, and it has two nodes: head and tail. Initially, head and tail will point to null.
minimumNode() will prints out minimum value node:
1. Define variable min and initialize with head’s data.
2. Current will point to head.
3. Iterate through the list by comparing each node’s data with min.
4. If min > current’s data then min will hold current’s data.
5. At the end of the list, variable min will hold the minimum value node.
6. Print the min value.
maximumNode() will prints out maximum value node:
1. Define variable max and initialize with head’s data.
2. Current will point to head.
3. Iterate through the list by comparing each node’s data with max.
4. If max < current’s data then max will hold current?s data.
5. At the end of the list, variable max will hold the maximum value node.
6. Print the max value.

Solution

Python

  #Represent a node of doubly linked list  class Node:      def __init__(self,data):          self.data = data;          self.previous = None;          self.next = None;            class MinMax:      #Represent the head and tail of the doubly linked list      def __init__(self):          self.head = None;          self.tail = None;                #addNode() will add a node to the list      def addNode(self, data):          #Create a new node          newNode = Node(data);                    #If list is empty          if(self.head == None):              #Both head and tail will point to newNode              self.head = self.tail = newNode;              #head’s previous will point to None              self.head.previous = None;              #tail’s next will point to None, as it is the last node of the list              self.tail.next = None;          else:              #newNode will be added after tail such that tail’s next will point to newNode              self.tail.next = newNode;              #newNode’s previous will point to tail              newNode.previous = self.tail;              #newNode will become new tail              self.tail = newNode;              #As it is last node, tail’s next will point to None              self.tail.next = None;                    #MinimumNode() will find out minimum value node in the list      def minimumNode(self):          #Node current will point to head          current = self.head;                    #Checks if list is empty          if(self.head == None):              print(“List is empty”);              return 0;          else:              #Initially, min will store the value of head’s data              min = self.head.data;              while(current != None):                  #If value of min is greater than current’s data                  #Then, replace value of min with current node’s data                  if(min > current.data):                      min = current.data;                  current = current.next;          return min;                #MaximumNode() will find out maximum value node in the list      def maximumNode(self):          #Node current will point to head          current = self.head;                    #Checks if list is empty          if(self.head == None):              print(“List is empty”);              return 0;          else:              #Initially, max will store the value of head’s data              max = self.head.data;              #If value of max is lesser than current’s data              #Then, replace value of max with current node’s data              while(current != None):                  if(current.data > max):                      max = current.data;                  current = current.next;          return max;                dList = MinMax();  #Add nodes to the list  dList.addNode(5);  dList.addNode(7);  dList.addNode(9);  dList.addNode(1);  dList.addNode(2);     #Prints the minimum value node in the list  print(“Minimum value node in the list: “+ str(dList.minimumNode()));  #Prints the maximum value node in the list  print(“Maximum value node in the list: “+ str(dList.maximumNode()));  

Output:

Minimum value node in the list: 1  Maximum value node in the list: 9

C

  #include <stdio.h>     //Represent a node of the doubly linked list    struct node{      int data;      struct node *previous;      struct node *next;  };         //Represent the head and tail of the doubly linked list  struct node *head, *tail = NULL;     //addNode() will add a node to the list  void addNode(int data) {      //Create a new node      struct node *newNode = (struct node*)malloc(sizeof(struct node));      newNode->data = data;            //If list is empty      if(head == NULL) {          //Both head and tail will point to newNode          head = tail = newNode;          //head’s previous will point to NULL          head->previous = NULL;          //tail’s next will point to NULL, as it is the last node of the list          tail->next = NULL;      }      else {          //newNode will be added after tail such that tail’s next will point to newNode          tail->next = newNode;          //newNode’s previous will point to tail          newNode->previous = tail;          //newNode will become new tail          tail = newNode;          //As it is last node, tail’s next will point to NULL          tail->next = NULL;      }  }     //MinimumNode() will find out minimum value node in the list  int minimumNode() {      //Node current will point to head      struct node *current = head;      int min;            //Checks if list is empty      if(head == NULL) {          printf(“List is emptyn”);          return 0;      }      else {          //Initially, min will store the value of head’s data          min = head->data;          while(current != NULL) {              //If value of min is greater than current’s data              //Then, replace value of min with current node’s data              if(min > current->data)                  min = current->data;              current = current->next;          }      }      return min;  }     //MaximumNode() will find out maximum value node in the list  int maximumNode() {      //Node current will point to head      struct node *current = head;      int max;            //Checks if list is empty      if(head == NULL) {          printf(“List is emptyn”);          return 0;      }      else {          //Initially, max will store the value of head’s data          max = head->data;          //If value of max is lesser than current’s data          //Then, replace value of max with current node’s data          while(current != NULL) {              if(current->data > max)                   max = current->data;              current = current->next;          }      }      return max;  }     int main()  {      //Add nodes to the list      addNode(5);      addNode(7);      addNode(9);      addNode(1);      addNode(2);            //Prints the minimum value node in the list      printf(“Minimum value node in the list: %dn”, minimumNode());      //Prints the maximum value node in the list      printf(“Maximum value node in the list: %d”, maximumNode());         return 0;  }  

Output:

Minimum value node in the list: 1  Maximum value node in the list: 9

JAVA

  public class MinMax {            //Represent a node of the doubly linked list        class Node{          int data;          Node previous;          Node next;                    public Node(int data) {              this.data = data;          }      }            //Represent the head and tail of the doubly linked list      Node head, tail = null;            //addNode() will add a node to the list      public void addNode(int data) {          //Create a new node          Node newNode = new Node(data);                    //If list is empty          if(head == null) {              //Both head and tail will point to newNode              head = tail = newNode;              //head’s previous will point to null              head.previous = null;              //tail’s next will point to null, as it is the last node of the list              tail.next = null;          }          else {              //newNode will be added after tail such that tail’s next will point to newNode              tail.next = newNode;              //newNode’s previous will point to tail              newNode.previous = tail;              //newNode will become new tail              tail = newNode;              //As it is last node, tail’s next will point to null              tail.next = null;          }      }            //MinimumNode() will find out minimum value node in the list      public int minimumNode() {          //Node current will point to head          Node current = head;          int min;                    //Checks if list is empty          if(head == null) {              System.out.println(“List is empty”);              return 0;          }          else {              //Initially, min will store the value of head’s data              min = head.data;              while(current != null) {                  //If the value of min is greater than the current’s data                    //Then, replace the value of min with current node’s data                    if(min > current.data)                      min = current.data;                  current = current.next;              }          }          return min;      }            //MaximumNode() will find out maximum value node in the list      public int maximumNode() {          //Node current will point to head          Node current = head;          int max;                    //Checks if list is empty          if(head == null) {              System.out.println(“List is empty”);              return 0;          }          else {              //Initially, max will store the value of head’s data              max = head.data;              //If value of max is lesser than current’s data              //Then, replace value of max with current node’s data              while(current != null) {                  if(current.data > max)                       max = current.data;                  current = current.next;              }          }          return max;      }            public static void main(String[] args) {                    MinMax dList = new MinMax();          //Add nodes to the list          dList.addNode(5);          dList.addNode(7);          dList.addNode(9);          dList.addNode(1);          dList.addNode(2);                    //Prints the minimum value node in the list          System.out.println(“Minimum value node in the list: “+ dList.minimumNode());          //Prints the maximum value node in the list          System.out.println(“Maximum value node in the list: “+ dList.maximumNode());      }  }  

Output:

Minimum value node in the list: 1  Maximum value node in the list: 9

C#

  using System;   namespace DoublyLinkedList   {                           public class Program      {          //Represent a node of the doubly linked list            public class Node<T>{              public T data;              public Node<T> previous;              public Node<T> next;                            public Node(T value) {                  data = value;              }          }                    public class MinMax<T> where T : IComparable<T>{              //Represent the head and tail of the doubly linked list              protected Node<T> head = null;                            protected Node<T> tail = null;                            //addNode() will add a node to the list              public void addNode(T data) {                  //Create a new node                  Node<T> newNode = new Node<T>(data);                     //If list is empty                  if(head == null) {                      //Both head and tail will point to newNode                      head = tail = newNode;                      //head’s previous will point to null                      head.previous = null;                      //tail’s next will point to null, as it is the last node of the list                      tail.next = null;                  }                  else {                      //newNode will be added after tail such that tail’s next will point to newNode                      tail.next = newNode;                      //newNode’s previous will point to tail                      newNode.previous = tail;                      //newNode will become new tail                      tail = newNode;                      //As it is last node, tail’s next will point to null                      tail.next = null;                  }              }                            //MinimumNode() will find out minimum value node in the list              public T minimumNode() {                  //Node current will point to head                  Node<T> current = head;                  T min;                     //Checks if list is empty                  if(head == null) {                      Console.WriteLine(“List is empty”);                      return default(T);                  }                  else {                      //Initially, min will store the value of head’s data                      min = head.data;                      while(current != null) {                          //If value of min is greater than current’s data                          //Then, replace value of min with current node’s data                          if(min.CompareTo(current.data) > 0)                              min = current.data;                          current = current.next;                      }                  }                  return min;              }                    //MaximumNode() will find out maximum value node in the list              public T maximumNode() {                  //Node current will point to head                  Node<T> current = head;                  T max;                     //Checks if list is empty                  if(head == null) {                      Console.WriteLine(“List is empty”);                      return default(T);                  }                  else {                      //Initially, max will store the value of head’s data                      max = head.data;                      //If value of max is lesser than current’s data                      //Then, replace value of max with current node’s data                      while(current != null) {                          if(current.data.CompareTo(max) > 0)                               max = current.data;                          current = current.next;                      }                  }                  return max;              }          }                    public static void Main()          {              MinMax<int> dList = new MinMax<int>();              //Add nodes to the list              dList.addNode(5);              dList.addNode(7);              dList.addNode(9);              dList.addNode(1);              dList.addNode(2);                 //Prints the minimum value node in the list              Console.WriteLine(“Minimum value node in the list: “+ dList.minimumNode());              //Prints the maximum value node in the list              Console.WriteLine(“Maximum value node in the list: “+ dList.maximumNode());          }          }  }             

Output:

Minimum value node in the list: 1  Maximum value node in the list: 9

PHP

  <!DOCTYPE html>  <html>  <body>  <?php  //Represent a node of doubly linked list  class Node{      public $data;      public $previous;      public $next;            function __construct($data){          $this->data = $data;      }  }  class MinMax{      //Represent the head and tail of the doubly linked list      public $head;      public $tail;      function __construct(){          $this->head = NULL;          $this->tail = NULL;      }            //addNode() will add a node to the list      function addNode($data){          //Create a new node          $newNode = new Node($data);                    //If list is empty          if($this->head == NULL) {              //Both head and tail will point to newNode              $this->head = $this->tail = $newNode;              //head’s previous will point to NULL              $this->head->previous = NULL;              //tail’s next will point to NULL, as it is the last node of the list              $this->tail->next = NULL;          }          else {              //newNode will be added after tail such that tail’s next will point to newNode              $this->tail->next = $newNode;              //newNode’s previous will point to tail              $newNode->previous = $this->tail;              //newNode will become new tail              $this->tail = $newNode;              //As it is last node, tail’s next will point to NULL              $this->tail->next = NULL;          }      }            //MinimumNode() will find out minimum value node in the list      function minimumNode() {          //Node current will point to head          $current = $this->head;                    //Checks if list is empty          if($this->head == NULL) {              print(“List is empty <br>”);              return 0;          }          else {              //Initially, min will store the value of head’s data              $min = $this->head->data;              while($current != NULL) {                  //If value of min is greater than current’s data                  //Then, replace value of min with current node’s data                  if($min > $current->data)                      $min = $current->data;                  $current = $current->next;              }          }          return $min;      }            //MaximumNode() will find out maximum value node in the list      function maximumNode() {          //Node current will point to head          $current = $this->head;                    //Checks if list is empty          if($this->head == NULL) {              print(“List is empty <br>”);              return 0;          }          else {              //Initially, max will store the value of head’s data              $max = $this->head->data;              //If value of max is lesser than current’s data              //Then, replace value of max with current node’s data              while($current != NULL) {                  if($current->data > $max)                       $max = $current->data;                  $current = $current->next;              }          }          return $max;      }  }        $dList = new MinMax();  //Add nodes to the list  $dList->addNode(5);  $dList->addNode(7);  $dList->addNode(9);  $dList->addNode(1);  $dList->addNode(2);     //Prints the minimum value node in the list  print(“Minimum value node in the list: ” . $dList->minimumNode());  print(“<br>”);  //Prints the maximum value node in the list  print(“Maximum value node in the list: ” . $dList->maximumNode());  ?>  </body>  </html>  

Output:

Minimum value node in the list: 1  Maximum value node in the list: 9

Next Topic#

Q. Program to find the maximum and minimum value node from a doubly linked list.

Explanation

Algorithm

Solution

Python

C

JAVA

C#

PHP

Potential Energy

Program to Find The Transpose of a Given Matrix

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