스택 Stack

스택 Stack

class Node {
  constructor(value){
    this.valeue = value;
    this.next = null;    
  }
}

class Stack {
  construtor(){
    this.first = null;
    this.last = null;
    this.size = 0;
  }
  push(val){
    let newNode = new Node(val);
    if(!this.first){
      this.first = newNode
      this.last = newNode;
    }else{
      let temp = this.first;
      this.first = newNode;
      this.first.next = temp;
    }
    return ++this.size;
  }
  pop(){
    if(!this.first) return null;
    let temp = this.first;
    if(this.first === this.last){
      this.last = null;
    }
    this.first = this.first.next;
    this.size--;
    return temp.value;
  }
}

const test = new Stack()
test.push(1);
test.push(2);
test.push(3);
// test.push(2)
test.pop();

console.log(test,"확인중@@")