Test 1 – 20113 Q4

stack.h

#pragma once
#include 
using namespace std;
class Stack;
class Node{
  int _data;
  Node* _next;
  Node(int data, Node* next);
  friend class Stack;
};
 
class Stack{
  Node* _top;
public:
 Stack();
  void push(int data);
  int pop();
  bool isEmpty();
  int depth();
  bool delNode(int num); 
  int append(int );
  virtual ~Stack();
};

stack.cpp

#include "stack.h"
Node::Node(int data, Node* next){
  _data = data;
  _next = next;
}
Stack::Stack(){
  _top = (Node*)0;
}
void Stack::push(int data){
 Node* tempnode = new Node(data, _top);
 _top = tempnode;
}
int Stack::pop(){
  int ret = _top->_data;
  Node* toDel = _top;
  _top = _top->_next;
  delete toDel;
  return ret;
}
int Stack::depth(){
  int ret=0;
  Node* temp=_top;
  while(temp){
   ret += !!(temp);
   temp=temp->_next;
  }
  return ret;
}
bool Stack:: delNode(int num){
 int i;
 bool done = false;
 Node* cur =_top;
    Node* prev = (Node*)0;
 for(i=1; cur != (Node*)0 && !done && i<=num; i++){
    if(i == num ){
      Node* toDel= cur;
      if(cur == _top){
        pop();
        done = true;
      }
      else {
        prev->_next = cur->_next;
        delete toDel;
        done = true;
      }
    }
    else {
      prev = cur;
      cur = cur->_next;
    }
  }
  return done;
}
int Stack:: append(int data){
   if(_top){
  Node* temp = _top;
  Node* Last = _top;
  while(temp){
  Last = temp;
  temp = temp->_next;
  }
  Last->_next = new Node(data, (Node*)0); 
 }else
  push(data);
 return data;
 }
bool Stack::isEmpty(){
  return _top == (Node*)0;
}
Stack::~Stack(){
  while(!isEmpty()) pop();
}