Using “unique()” on a vector of vectors in C++

Question

I hope this is not a duplicate question, but if it is, feel free to point me in the right direction.

I have a vector >.

Is i

Answer 1

Yes, as long as your vector is sorted. See unique () STL documentation for details.

Here is an example of usage:

#include 
#include 
#include 
#include 
#include 

using namespace std;

int main ()
{
    vector< vector > v;

    v.push_back (vector ());
    v.back ().push_back ("A");

    v.push_back (vector ());
    v.back ().push_back ("A");

    v.push_back (vector ());
    v.back ().push_back ("B");

    for (vector< vector >::iterator it = v.begin (); it != v.end (); ++it)
        for (vector::iterator j = it->begin (), j_end = it->end (); j != j_end; ++j)
            cout << *j << endl;

    cout << "-------" << endl;

    vector< vector >::iterator new_end = unique (v.begin (), v.end ());
    for (vector< vector >::iterator it = v.begin (); it != new_end; ++it)
        for (vector::iterator j = it->begin (), j_end = it->end (); j != j_end; ++j)
            cout << *j << endl;
}