class Node {
constructor(val) {
this.val = val;
this.next = null;
}
}
class SinglyLinkedList {
constructor(){
this.head = null;
this.tail = null;
this.length = 0;
}
push(val) {
var newNode = new Node(val);
if(!this.head) {
this.head = newNode;
this.tail = this.head
} else {
this.tail.next = newNode;
this.tail = newNode;
}
this.length++;
return this;
}
pop() {
var current = this.head;
var newTail = current;
while(current.next) {
newTail = current;
current = current.next;
}
this.tail = newTail;
this.tail.next = null;
this.length--;
if(this.length === 0) {
this.head = null;
this.tail = null;
}
return current;
}
}
var list = new SinglyLinkedList();
list.push("Hi");
list.push("there");
list.push("!");
console.log(list.pop());
/* Popping pseudocode
- If there are no nodes in the list, return undefined
- Loop through the list until you reach the tail
- Set the next property to the second to the last node to be null
- Set the tail to be second to the last node
- Decrement the length of the list by 1
- Return the value of the node removed
*/
