Vector 嵌套

int main()
{
    int n,m,k;
    cin>>n>>m;
    vector< vector<int> > vc;
    rep(1,n)
    {
        vector<int>vec;
        for(int j=0;j<=m;j++)
        {
            cn(k);
            vec.push_back(k);
        }
        vc.push_back(vec);
    }
    rep(0,n-1)
    {
        for(int j=0;j<=m;j++)
            ct vc[i][j] <<" ";
        ct endl ;
    }
    vector< vector<int> >::iterator iter;
    vector<int>::iterator it;
    for(iter=vc.begin();iter!=vc.end();iter++)
    {
        for(it=(*iter).begin();it<(*iter).end();it++)
            ct *it <<" ";
        ct endl;
    }
}

2 3
1 2 3 4
5 6 7 8
1 2 3 4
5 6 7 8
1 2 3 4
5 6 7 8

int main()
{
    int n,k;
    cin>>n>>m;
    vector< vector<int> > vc;
    vector<int>vec;
    rep(1,n)
    {
        for(int j=0;j<=m;j++)
        {
            cn(k);
            vec.push_back(k);
        }
        vc.push_back(vec);
    }
    
    rep(0,n-1)
    {
        for(int j=0;j<=m;j++)
            ct vc[i][j] <<" ";
        ct endl ;
    }
    
    vector< vector<int> >::iterator iter;
    vector<int>::iterator it;
    for(iter=vc.begin();iter!=vc.end();iter++)
    {
        for(it=(*iter).begin();it<(*iter).end();it++)
            ct *it <<" ";
        ct endl;
    }
}

2 3
1 2 3 4
5 6 7 8
1 2 3 4
1 2 3 4
1 2 3 4
1 2 3 4 5 6 7 8