{"id":26869,"date":"2017-12-26T20:40:32","date_gmt":"2017-12-26T15:10:32","guid":{"rendered":"https:\/\/www.wikitechy.com\/technology\/?p=26869"},"modified":"2017-12-26T20:40:32","modified_gmt":"2017-12-26T15:10:32","slug":"java-algorithm-find-length-linked-list-iterative-recursive","status":"publish","type":"post","link":"https:\/\/www.wikitechy.com\/technology\/java-algorithm-find-length-linked-list-iterative-recursive\/","title":{"rendered":"Java Algorithm – Find Length of a Linked List both Iterative and Recursive"},"content":{"rendered":"

Write a C function to count number of nodes in a given singly linked list.<\/p>\n

\"C<\/p>\n

For example, the function should return 5 for linked list 1->3->1->2->1.<\/p>\n

Iterative Solution<\/strong><\/p>\n

1) Initialize count as 0 \r\n2) Initialize a node pointer, current = head.\r\n3) Do following while current is not NULL\r\n     a) current = current -> next\r\n     b) count++;\r\n4) Return count<\/pre>\n
Java Programming:<\/strong><\/p>\n
 
 <\/div> 
\/\/ Java program to count number of nodes in a linked list \/* Linked list Node*\/class Node{    int data;    Node next;    Node(int d)  { data = d;  next = null; }} \/\/ Linked List classclass LinkedList{    Node head;  \/\/ head of list     \/* Inserts a new Node at front of the list. *\/    public void push(int new_data)    {        \/* 1 & 2: Allocate the Node &                  Put in the data*\/        Node new_node = new Node(new_data);         \/* 3. Make next of new Node as head *\/        new_node.next = head;         \/* 4. Move the head to point to new Node *\/        head = new_node;    }     \/* Returns count of nodes in linked list *\/    public int getCount()    {        Node temp = head;        int count = 0;        while (temp != null)        {            count++;            temp = temp.next;        }        return count;    }     \/* Drier program to test above functions. Ideally       this function should be in a separate user class.       It is kept here to keep code compact *\/    public static void main(String[] args)    {        \/* Start with the empty list *\/        LinkedList llist = new LinkedList();        llist.push(1);        llist.push(3);        llist.push(1);        llist.push(2);        llist.push(1);         System.out.println("Count of nodes is " +                           llist.getCount());    }}<\/code><\/pre> <\/div>\n[ad type=”banner”]\n
Output:<\/strong><\/p>\n
count of nodes is 5<\/pre>\n
Recursive Solution<\/strong><\/p>\n
int getCount(head)<\/strong>\r\n1) If head is NULL, return 0.\r\n2) Else return 1 + getCount(head->next)<\/pre>\n
Java Programming:<\/strong><\/p>\n
 
 <\/div> 
\/\/ Recursive Java program to count number of nodes in \/\/ a linked list \/* Linked list Node*\/class Node{    int data;    Node next;    Node(int d)  { data = d;  next = null; }} \/\/ Linked List classclass LinkedList{    Node head;  \/\/ head of list     \/* Inserts a new Node at front of the list. *\/    public void push(int new_data)    {        \/* 1 & 2: Allocate the Node &                  Put in the data*\/        Node new_node = new Node(new_data);         \/* 3. Make next of new Node as head *\/        new_node.next = head;         \/* 4. Move the head to point to new Node *\/        head = new_node;    }     \/* Returns count of nodes in linked list *\/    public int getCountRec(Node node)    {        \/\/ Base case        if (node == null)            return 0;         \/\/ Count is this node plus rest of the list        return 1 + getCountRec(node.next);    }     \/* Wrapper over getCountRec() *\/    public int getCount()    {        return getCountRec(head);    }     \/* Drier program to test above functions. Ideally       this function should be in a separate user class.       It is kept here to keep code compact *\/    public static void main(String[] args)    {        \/* Start with the empty list *\/        LinkedList llist = new LinkedList();        llist.push(1);        llist.push(3);        llist.push(1);        llist.push(2);        llist.push(1);         System.out.println("Count of nodes is " +                           llist.getCount());    }}<\/code><\/pre> <\/div>\n[ad type=”banner”]\n
Output:<\/strong><\/p>\n
count of nodes is 5<\/pre>\n","protected":false},"excerpt":{"rendered":"
Java Algorithm – Find Length of a Linked List both Iterative and Recursive – Linked List – Write a C function to count number of nodes in a given singly<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1,2139,79476,79478],"tags":[72483,80240,80236,80239,80231,80237,80241,80232,80238,80235,80234,80230,80233],"class_list":["post-26869","post","type-post","status-publish","format-standard","hentry","category-coding","category-java","category-linked-list","category-singly-linked-list","tag-c-linked-list","tag-find-length-of-linked-list-java","tag-geeksforgeeks","tag-get-length-of-linked-list-python","tag-how-to-calculate-the-length-of-linked-list-without-using-counter-in-java","tag-how-to-find-the-length-of-a-linked-list-python","tag-length-of-linked-list-c","tag-length-of-linked-list-python","tag-linked-list-implementation-in-python","tag-linkedlist-java","tag-recursive-linked-list-java","tag-size-of-linked-list-c","tag-what-is-a-class-loader-what-does-it-do"],"_links":{"self":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts\/26869","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/comments?post=26869"}],"version-history":[{"count":0,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/posts\/26869\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/media?parent=26869"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/categories?post=26869"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.wikitechy.com\/technology\/wp-json\/wp\/v2\/tags?post=26869"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}