#include <iostream>
#include <iterator>
#include <algorithm>
#include <vector>
using namespace std;

ostream& operator<<(ostream& out, const vector<int>& v)
{
    copy(v.cbegin(),v.cend(),ostream_iterator<int>(out," "));
    out << endl;
    return out;
}

bool abs_lt (int i,int j)
{
    return abs(i) < abs(j);
}

class MyLessThan
{
public:
    bool operator() (int i,int j)
    {
        return i < j;
    }
};

int main()
{
    int myints[] = {32,-71,12,45,-26,80,-53,33};
    vector<int> myvector (myints, myints+8);
    cout << "1) " << myvector << endl;

    // using default comparison (operator <):
    sort (myvector.begin(), myvector.begin()+4);
    cout << "2) " << myvector << endl;

    // using function as std compare function object
    sort (myvector.begin(), myvector.end(), greater<int>());
    cout << "3) " << myvector << endl;

    // using function
    sort (myvector.begin(), myvector.end(), abs_lt);
    cout << "4) " << myvector << endl;

    // using function object (functor)
    MyLessThan object;
    sort (myvector.begin(), myvector.end(), object);
    cout << "5) " << myvector << endl;
}