vector<int>::const_iterator it; // it can NOT be changed

for(it = nums.begin(); it != nums.end(); it++) {

// *it = 4; // wrong!

cout << *it << " ";

}

cout << endl;

vector<int>::iterator it; // it can be changed

for(it = nums.begin(); it != nums.end(); it++) {

*it = 4; // ok!

cout << *it << " ";

}

cout << endl;

vector<int>::reverse_iterator rit;

for(rit = nums.rbegin(); rit != nums.rend(); rit++) {

cout << *rit << " ";

}

cout << endl;

const vector<int> nums = {1, 2, 3, 4, 5};

test_iterator(nums);

test_const_iterator(nums);

test_revers_iterator(nums);

return 0;

}