Answers for "c++ vector explained"

vector in c++

vector<int> g1; 
  
    for (int i = 1; i <= 5; i++) 
        g1.push_back(i); 
  
    cout << "Output of begin and end: "; 
    for (auto i = g1.begin(); i != g1.end(); ++i) 
        cout << *i << " "; 
  
    cout << "nOutput of cbegin and cend: "; 
    for (auto i = g1.cbegin(); i != g1.cend(); ++i) 
        cout << *i << " "; 
  
    cout << "nOutput of rbegin and rend: "; 
    for (auto ir = g1.rbegin(); ir != g1.rend(); ++ir) 
        cout << *ir << " ";

vector operations in c++

#include <iostream>
#include<vector>
#include<algorithm>

using namespace std;

int main()
{
    int n;
    cin>>n;
    vector<int>vec(n);
    for(int i=0;i<n;i++)
    {
        cin>>vec[i];
    }
    cout<<"----------"<<endl;
    for(int i=0;i<n;i++)
    {
      cout<<vec[i]<<" ";
    }
    vec.push_back(100);
    vec.push_back(200);
    cout<<endl;
    auto it=vec.begin();
    vec.insert(it,3,1000);
    for(vector<int>::iterator it1=vec.begin();it1!=vec.end();it1++)
    {
        cout<<*it1<<" ";
    }
    cout<<endl;
    vector<int>vec2;
    vec2.push_back(15);
    vec2.push_back(25);
    vec2.push_back(35);
    vec.insert(it,vec2.begin(),vec2.end());
    for(vector<int>::iterator it1=vec.begin();it1!=vec.end();it1++)
    {
        cout<<*it1<<" ";
    }
    cout<<endl;
    vec.pop_back();
    vec.pop_back();
    for(vector<int>::iterator it1=vec.begin();it1!=vec.end();it1++)
    {
        cout<<*it1<<" ";
    }
    cout<<endl;
    int k;
    cin>>k;
    cout<<endl;
    vector<int>::iterator its=vec.begin()+k-1;
    int s=vec.size();
    cout<<s<<endl;
    vec.erase(its);
    for(vector<int>::iterator it1=vec.begin();it1!=vec.end();it1++)
    {
        cout<<*it1<<" ";
    }
    

    return 0;
}