C++ Primer (5th) 3.21

#include <iostream>
#include <vector>
using namespace std;
using std::vector;

int main(int argc, char const *argv[])
{
    vector<int> v1;
    vector<int> v2(10);
    vector<int> v3(10, 42);
    vector<int> v4{10};
    vector<int> v5{10, 42};
    vector<string> v6{10};
    vector<string> v7{10, "Hi"};

    vector<vector<int> > ivec = {v1, v2, v3, v4, v5};
    vector<vector<string> > svec = {v6, v7};

    int temp = 0;
    for (auto iter = ivec.begin(); iter != ivec.end(); ++iter)
    {
        ++temp;
        if(iter->empty())
        {
            cout << "V" << temp << "is empty!" << endl;
        }
        else
        {
            int i = 0;
            cout << "V" << temp << " is ->" << endl;
            for(auto it = (*iter).begin(); it != (*iter).end(); ++it)   
            {
                ++i;
                cout << "Number_"<< i << " is  ";
                cout << *it << endl;
            }
        }
    }

    for (auto iter = svec.begin(); iter != svec.end(); ++iter)
    {
        ++temp;
        if(iter->empty())
        {
            cout << "V" << temp << "is empty!" << endl;
        }
        else
        {
            int i = 0;
            cout << "V" << temp << " is ->" << endl;
            for(auto it = (*iter).begin(); it != (*iter).end(); ++it)   
            {
                ++i;
                cout << "String_"<< i << " is  ";
                cout << *it << endl;
            }
        }
    }
    // for (int i = 0; i != 5; ++i)
    // {
    //     if (ivec[i].empty())
    //     {
    //         cout << "v" << i + 1 << " is empty!" << endl;
    //     }
    //     else
    //     {
    //         cout << "v" << i + 1 << " is begin" << endl;
    //         for (int j = 0; j != ivec[i].size(); ++j)
    //         {
    //             vector<int> temp;
    //             temp = ivec[i];
    //             cout << temp[j];
    //             cout << "-->";
    //             cout << endl;
    //         }
    //     }
    // }

    // for (int i = 0; i != 2; ++i)
    // {
    //     if (svec[i].empty())
    //     {
    //         cout << "v" << i + 6 << " is empty!" << endl;
    //     }
    //     else
    //     {
    //         cout << "v" << i + 6 << " is begin" << endl;
    //         for (int j = 0; j != svec[i].size(); ++j)
    //         {
    //             vector<string> temp;
    //             temp = svec[i];
    //             cout << temp[j];
    //             cout << "-->";
    //             cout << endl;
    //         }
    //     }
    // }




    system("pasue");
    return 0;
}