i would like to ask how do you iterate over vector of vector of pair? supposed i have the following.

```
typedef pair<int,int> Pair;
vector<vector<Pair> > adjList;

```

and then i tried to iterate using the following code:

```
vector<vector<Pair> > :: iterator i;
vector<Pair> :: iterator it;
for(i = adjList[N].begin(); i != adjList[N].end(); ++i)
{
   for(it = adjList[N].begin(); it != adjList[N].end(); ++it)
   //and the rest of the code

```

however it returns an error 

```
'no match for ‘operator=’ (operand types are ‘std::vector > >::iterator {aka __gnu_cxx::__normal_iterator >*, std::vector > > >}’ and ‘std::vector >::iterator {aka __gnu_cxx::__normal_iterator*, std::vector > >}’)'. 

```

anyone knows? thanks.