mirror of
https://github.com/TheAlgorithms/JavaScript.git
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Merge branch 'master' into master
This commit is contained in:
vinayak
@@ -1,195 +1,198 @@
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// Hamza chabchoub contribution for a university project
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function doubleLinkedList () {
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const Node = function (element) {
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this.element = element
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this.next = null
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this.prev = null
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}
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let length = 0
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let head = null
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let tail = null
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// Add new element
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this.append = function (element) {
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const node = new Node(element)
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if (!head) {
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head = node
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tail = node
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} else {
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node.prev = tail
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tail.next = node
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tail = node
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//Hamza chabchoub contribution for a university project
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function doubleLinkedList() {
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let Node = function(element) {
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this.element = element;
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this.next = null;
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this.prev = null;
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}
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length++
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}
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// Add element
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this.insert = function (position, element) {
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// Check of out-of-bound values
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if (position >= 0 && position <= length) {
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const node = new Node(element)
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let current = head
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let previous
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let index = 0
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if (position === 0) {
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if (!head) {
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head = node
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tail = node
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} else {
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node.next = current
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current.prev = node
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head = node
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let length = 0;
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let head = null;
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let tail = null;
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//Add new element
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this.append = function(element) {
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let node = new Node(element);
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if(!head){
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head = node;
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tail = node;
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}else{
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node.prev = tail;
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tail.next = node;
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tail = node;
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}
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length++;
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}
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//Add element
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this.insert = function(position, element) {
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//Check of out-of-bound values
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if(position >= 0 && position <= length){
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let node = new Node(element),
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current = head,
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previous,
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index = 0;
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if(position === 0){
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if(!head){
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head = node;
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tail = node;
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}else{
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node.next = current;
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current.prev = node;
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head = node;
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}
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}else if(position === length){
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current = tail;
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current.next = node;
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node.prev = current;
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tail = node;
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}else{
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while(index++ < position){
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previous = current;
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current = current.next;
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}
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node.next = current;
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previous.next = node;
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//New
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current.prev = node;
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node.prev = previous;
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}
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} else if (position === length) {
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current = tail
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current.next = node
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node.prev = current
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tail = node
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} else {
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while (index++ < position) {
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previous = current
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current = current.next
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}
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node.next = current
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previous.next = node
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// New
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current.prev = node
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node.prev = previous
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length++;
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return true;
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}else{
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return false;
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}
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length++
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return true
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} else {
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return false
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}
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}
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// Remove element at any position
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this.removeAt = function (position) {
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// look for out-of-bounds value
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if (position > -1 && position < length) {
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let current = head; let previous; let index = 0
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// Removing first item
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if (position === 0) {
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head = current.next
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// if there is only one item, update tail //NEW
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if (length === 1) {
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tail = null
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} else {
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head.prev = null
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//Remove element at any position
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this.removeAt = function(position){
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//look for out-of-bounds value
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if(position > -1 && position < length){
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let current = head, previous, index = 0;
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//Removing first item
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if(position === 0){
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head = current.next;
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//if there is only one item, update tail //NEW
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if(length === 1){
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tail = null;
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}else{
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head.prev = null;
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}
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}else if(position === length - 1){
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current = tail;
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tail = current.prev;
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tail.next = null;
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}else{
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while(index++ < position){
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previous = current;
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current = current.next;
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}
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//link previous with current's next - skip it
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previous.next = current.next;
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current.next.prev = previous;
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}
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} else if (position === length - 1) {
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current = tail
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tail = current.prev
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tail.next = null
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} else {
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while (index++ < position) {
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previous = current
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current = current.next
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length--;
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return current.element;
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}else{
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return null;
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}
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}
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//Get the indexOf item
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this.indexOf = function(elm){
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let current = head,
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index = -1;
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//If element found then return its position
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while(current){
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if(elm === current.element){
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return ++index;
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}
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// link previous with current's next - skip it
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previous.next = current.next
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current.next.prev = previous
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index++;
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current = current.next;
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}
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//Else return -1
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return -1;
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};
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//Find the item in the list
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this.isPresent = (elm) => {
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return this.indexOf(elm) !== -1;
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};
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//Delete an item from the list
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this.delete = (elm) => {
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return this.removeAt(this.indexOf(elm));
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};
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//Delete first item from the list
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this.deleteHead = function(){
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this.removeAt(0);
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}
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//Delete last item from the list
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this.deleteTail = function(){
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this.removeAt(length-1);
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}
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//Print item of the string
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this.toString = function(){
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let current = head,
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string = '';
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while(current){
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string += current.element + (current.next ? '\n' : '');
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current = current.next;
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}
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length--
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return current.element
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} else {
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return null
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}
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}
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// Get the indexOf item
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this.indexOf = function (elm) {
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let current = head
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let index = -1
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// If element found then return its position
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while (current) {
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if (elm === current.element) {
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return ++index
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return string;
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};
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//Convert list to array
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this.toArray = function(){
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let arr = [],
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current = head;
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while(current){
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arr.push(current.element);
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current = current.next;
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}
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index++
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current = current.next
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return arr;
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};
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//Check if list is empty
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this.isEmpty = function(){
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return length === 0;
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};
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//Get the size of the list
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this.size = function(){
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return length;
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}
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// Else return -1
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return -1
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}
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// Find the item in the list
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this.isPresent = (elm) => {
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return this.indexOf(elm) !== -1
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}
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// Delete an item from the list
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this.delete = (elm) => {
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return this.removeAt(this.indexOf(elm))
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}
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// Delete first item from the list
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this.deleteHead = function () {
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this.removeAt(0)
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}
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// Delete last item from the list
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this.deleteTail = function () {
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this.removeAt(length - 1)
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}
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// Print item of the string
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this.toString = function () {
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let current = head
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let string = ''
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while (current) {
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string += current.element + (current.next ? '\n' : '')
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current = current.next
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//Get the head
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this.getHead = function() {
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return head;
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}
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return string
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}
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// Convert list to array
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this.toArray = function () {
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const arr = []
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let current = head
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while (current) {
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arr.push(current.element)
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current = current.next
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//Get the tail
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this.getTail = function() {
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return tail;
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}
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}
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return arr
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}
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// Check if list is empty
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this.isEmpty = function () {
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return length === 0
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}
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// Get the size of the list
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this.size = function () {
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return length
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}
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// Get the head
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this.getHead = function () {
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return head
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}
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// Get the tail
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this.getTail = function () {
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return tail
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}
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}
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