@@ -2,21 +2,22 @@ class Node {
22 constructor ( data , next ) {
33 this . data = data ;
44 this . next = next ;
5- this . length = 0 ;
65 }
76}
87
98class LinkedList {
109 constructor ( ) {
1110 this . head = null ;
1211 this . tail = null ;
12+ this . size = 0 ;
1313 }
1414
1515 addAtBeginning ( element ) {
1616 this . head = new Node ( element , this . head ) ;
1717 if ( ! this . tail ) {
1818 this . tail = this . head ;
1919 }
20+ this . size += 1 ;
2021 return this . head ;
2122 }
2223
@@ -27,19 +28,20 @@ class LinkedList {
2728 const node = new Node ( element , null ) ;
2829 this . tail . next = node ;
2930 this . tail = node ;
31+ this . size += 1 ;
3032 return node ;
3133 }
3234
3335 removeFromBeginning ( ) {
3436 if ( ! this . head ) {
35- this . tail = null ;
3637 return null ;
3738 }
3839 if ( this . head . next === null ) {
3940 this . tail = this . head ;
4041 }
4142 const node = this . head ;
4243 this . head = this . head . next ;
44+ this . size -= 1 ;
4345 return node ;
4446 }
4547
@@ -57,6 +59,7 @@ class LinkedList {
5759
5860 const node = this . tail . next ;
5961 this . tail . next = null ;
62+ this . size -= 1 ;
6063 return node ;
6164 }
6265
@@ -108,8 +111,10 @@ class LinkedList {
108111 count -= 1 ;
109112 }
110113
111- previous . next = new Node ( element , previous . next ) ;
112- return null ;
114+ const node = new Node ( element , previous . next ) ;
115+ previous . next = node ;
116+ this . size += 1 ;
117+ return node ;
113118 }
114119
115120 removeAt ( index ) {
@@ -133,21 +138,18 @@ class LinkedList {
133138
134139 const node = address ;
135140 previous . next = address . next . next ;
141+ this . size -= 1 ;
136142 return node ;
137143 }
138144
139145 length ( ) {
140- let address = this . head ;
141- let count = 0 ;
142- while ( address ) {
143- count += 1 ;
144- address = address . next ;
145- }
146- return count ;
146+ return this . size ;
147147 }
148148
149149 delete ( ) {
150150 this . head = null ;
151+ this . tail = this . head ;
152+ this . size = 0 ;
151153 }
152154}
153155
0 commit comments