vector_class.txt

Vector class:-



#include <iostream>
#include <bits/stdc++.h>

using namespace std;


class Vector{
  
  
  int*arr;
  int cs;
  int ms;
  public:
  Vector(){
      cs = 0;
      ms = 1;
      arr = new int[ms];
  }
  
  void push_back(int d){
      if(cs == ms){
        int *oldarr = arr;
        ms = 2*ms;
        arr = new int[ms];
        
        for(int i =0;i<cs;i++){
            arr[i] = oldarr[i];
        }
        delete oldarr;
      }
      arr[cs]=d;
      cs++;
  }
  
  void pop_back(){
      if(cs>=0)cs--;
      
  }
  bool isempty(){
      return cs==0;
  }
  
  int getfront(){
      return arr[0];
  }
  
  int back(){
      return arr[cs-1];
  }
  int size(){
      return cs;
  }
  int capacity(){
      return ms;
  }
    
    
    
    
};

int main()
{
    // vector<int> v = {1,2,3,4,5,6,7};
    
    // int key;
    // cin>>key;
    
    
    
    // vector<int>::iterator it = find(v.begin(),v.end(),key);
    
    // if(it!=v.end())cout<<it - v.begin();
    // else cout<<"element is not found";
    
    
    // vector<vector<int>>arr = {{1,2,3},
    //                           {4,5,6,7},
    //                           {8,9,10},
    //                           {11,12}};
                              
    // for(int i =0;i<arr.size();i++){
    //     for(int number : arr[i]){
    //         cout<<number<<" ";
    //     }
    //     cout<<endl;
    // }
    
    Vector v;
    v.push_back(1);
    v.push_back(2);
    v.push_back(3);
    v.push_back(4);
    v.push_back(5);
    
    cout<<v.size()<<endl;
    
    
    return 0;
}