copy some elements of a vector in reverse order

[tom]

Question:
Give a vector that has 10 elements, copy the elements from position 3
through 7 in reverse order to a list
I have a solution in the below, but I'm feel there could be a better
one, (just not quite confident with this one)

My answer:
==========
#include <iostream>
#include <vector>
#include <hash_map>
#include <cctype>
#include <cassert>
#include <fstream>
#include <sstream>
#include <list>
#include <deque>
#include <algorithm>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>

using namespace std;
using namespace stdext;

int main(int argc, char *argv[])
{
vector<int> intVector;
for(int i=0; i<10; i++)
{
intVector.push_back(i);
}

list<int> intList;
for(int i=3; i<=7; ++i)
{
intList.push_front(intVector);
}

ostream_iterator<int> oiter(cout, " ");
list<int>::const_iterator iter = intList.begin();
while(iter!=intList.end())
{
*oiter++ = *iter++;
}

return 0;
}

 

[Ondra Holub]

Question:
Give a vector that has 10 elements, copy the elements from position 3
through 7 in reverse order to a list
I have a solution in the below, but I'm feel there could be a better
one, (just not quite confident with this one)

My answer:
==========
#include <iostream>
#include <vector>
#include <hash_map>
#include <cctype>
#include <cassert>
#include <fstream>
#include <sstream>
#include <list>
#include <deque>
#include <algorithm>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>

using namespace std;
using namespace stdext;

int main(int argc, char *argv[])
{
vector<int> intVector;
for(int i=0; i<10; i++)
{
intVector.push_back(i);
}

list<int> intList;
for(int i=3; i<=7; ++i)
{
intList.push_front(intVector);
}

ostream_iterator<int> oiter(cout, " ");
list<int>::const_iterator iter = intList.begin();
while(iter!=intList.end())
{
*oiter++ = *iter++;
}

return 0;

}

copy(intVector.begin() + 3, intVector.begin() + 7 + 1,
front_inserter(intList));

 

[Ondra Holub]

Question:
Give a vector that has 10 elements, copy the elements from position 3
through 7 in reverse order to a list
I have a solution in the below, but I'm feel there could be a better
one, (just not quite confident with this one)

My answer:
==========
#include <iostream>
#include <vector>
#include <hash_map>
#include <cctype>
#include <cassert>
#include <fstream>
#include <sstream>
#include <list>
#include <deque>
#include <algorithm>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>

using namespace std;
using namespace stdext;

int main(int argc, char *argv[])
{
vector<int> intVector;
for(int i=0; i<10; i++)
{
intVector.push_back(i);
}

list<int> intList;
for(int i=3; i<=7; ++i)
{
intList.push_front(intVector);
}

ostream_iterator<int> oiter(cout, " ");
list<int>::const_iterator iter = intList.begin();
while(iter!=intList.end())
{
*oiter++ = *iter++;
}

return 0;

}

Or you can initialize list already in constructor, but you need
convert forward iterators to reverse_iterators:

list<int> intList(
vector<int>::reverse_iterator(intVector.begin() + 7 + 1),
vector<int>::reverse_iterator(intVector.begin() + 3)
);

 

[Frank Birbacher]

Hi!

Question:
Give a vector that has 10 elements, copy the elements from position 3
through 7 in reverse order to a list

Apart from Ondra's solutions: There is also a "copy_backward" algorithm:

http://www.sgi.com/tech/stl/copy_backward.html

Frank

 

[=?ISO-8859-1?Q?Erik_Wikstr=F6m?=]

Question:
Give a vector that has 10 elements, copy the elements from position 3
through 7 in reverse order to a list
I have a solution in the below, but I'm feel there could be a better
one, (just not quite confident with this one)

My answer:
==========
#include <iostream>
#include <vector>
#include <hash_map>
#include <cctype>
#include <cassert>
#include <fstream>
#include <sstream>
#include <list>
#include <deque>
#include <algorithm>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>

Do you always include all those headers, or did you post a part of some
bigger piece of code and forgot to delete the unused ones?