Thread: Implementing Library Algorithms

hey guys..need some help with a project...im basically to implement the following 5 algorithms for a driver program...

here are the algorithms:

accumulate(b, e, t)

equal(b, e, t)

fill(b, e, t) - is to copies the value t into all the elements in the range [b, e).

lexicographic_compare(b, e, b2, e2) - returns true if each element in the range [b, e) is less than the corresponding element in the range [b2, 2e), and false otherwise.

min_element(b, e) - min_element(b, e) returns an iterator pointing to the smallest element in the range [b, e).

this is what I have so far..

Code:

#ifndef GUARD_myalgorithm_h
#define GUARD_myalgorithm_h

template <class In, class Out>
Out my_copy(In b, In e, Out d)
{
while (b != e)
*d++ = *b++;
return d;
}

template <class In, class Out>
int my_accumulate(In b, In e, Out t)
{
int aaa = *t;
while (b != e) {
aaa = aaa + *b;
b++;
}
return aaa;
}

template <class In>
bool my_equal(In b, In e, In t)
{

return true;
}

template <class In>
void my_fill(In b, In e, In t)
{
while (b != e) {
*b = *t;
b++;
}
}

template <class In>
bool my_lexicographic_compare(In b, In e, In b2, In e2)
{
while (b != e && b2 != e2) {
for (b; b != e; b++)
  if (*b >= *b2)
return false;
if (*b < *b2)
}

template <class In>
iter my_min_element(In b, In e)
{
return;
}

#endif

can you guys go over it and see if there are mistakes, also i'm not sure how to do the min_element and equal functions so any pointers would help..thanks

ok i indented the code...and I also included the driver program - this should not be touched at all..

Code:

#ifndef GUARD_myalgorithm_h
#define GUARD_myalgorithm_h

template <class In, class Out>
Out my_copy(In b, In e, Out d)
{
    while (b != e) 
        *d++ = *b++;
    return d;
}


template <class In, class Out>
int my_accumulate(In b, In e, Out t)
{
    int aaa = *t;
    while (b != e) {
	aaa = aaa + *b;
	b++;
    }
    return aaa;
}

template <class In>
bool my_equal(In b, In e, In t)
{

    return true;
}

template <class In>
void my_fill(In b, In e, In t)
{
    while (b != e) {
	*b = *t;
	b++;
    }
}

template <class In>
bool my_lexicographic_compare(In b, In e, In b2, In e2)
{
    while (b != e && b2 != e2) {
	for (b; b != e; b++)
	    if (*b >= *b2)
		return false;
	if (*b < *b2)
	    return true;
    }
}
template <class In>
iter my_min_element(In b, In e)
{
    return;
}

#endif

program:

Code:

int main()
{
    // set up some vector and list objects to use 
    int a[] = {1, 2, 3, 4};
    size_t size_a = sizeof(a)/sizeof(*a);

    int b[] = {5, 6, 7};
    size_t size_b = sizeof(b)/sizeof(*b);

    int c[] = {4, 3, 2, 3, 4};
    size_t size_c = sizeof(c)/sizeof(*c);

    vector<int> va(a, a + size_a);
    vector<int> vb(b, b + size_b);
    vector<int> vc(c, c + size_c);

    list<int> la(a, a + size_a);
    list<int> lb(b, b + size_b);

    // test my_accumulate 
    cout << "test my_accumulate:\n";
    cout << "  The sum of the elements in va is "
         << my_accumulate(va.begin(), va.end(), 0) << endl;
    cout << "  The sum of the elements in lb is "
         << my_accumulate(lb.begin(), lb.end(), 0) << endl;

    // test my_equal
    cout << "\ntest my_equal:\n";
    if (my_equal(va.begin(), va.end(), vb.begin()))
        cout << "  va and vb are equal\n";
    else
        cout << "  va and vb are not equal\n";

    if (my_equal(va.begin(), va.end(), va.begin()))
        cout << "  va equals itself\n";
    else
        cout << "  va and lb are not equal\n";

    // test my_fill
    cout << "\ntest my_fill:\n";
    cout << "  original va: " ;
    my_copy(va.begin(), va.end(), ostream_it(cout, " "));
    cout << endl;

    my_fill(va.begin(), va.end(), 30);
    cout << "  modified va: ";
    my_copy(va.begin(), va.end(), ostream_it(cout, " "));
    cout << endl;

    // test my_lexicographic_compare
    cout << "\ntest my_lexicographic_compare:\n";

    if (my_lexicographic_compare(la.begin(), la.end(), lb.begin(), lb.end()))
        cout << "  la is less than lb\n";
    else
        cout << "  la is not less than lb\n";

    if (my_lexicographic_compare(va.begin(), va.end(), vb.begin(), vb.end()))
        cout << "  va is less than vb\n";
    else
        cout << "  va is not less than vb\n";

    // test my_min_element
    cout << "\ntest my_min_element:\n";
    cout << "  the smallest element of vc is "
         << *my_min_element(vc.begin(), vc.end())
         << endl;

    return 0;

}

sorry i need to keep the my_(name) cuz the project description tells me to do it like that...

Download UnitTest++ and write some automated unit tests to verify your code.

whats wrong with this piece of code? its giving me a compilation error saying "expected constructor, deconstructer, or type conversion before my_min_element"

Code:

template <class In>
iter my_min_element(In b, In e)
{
    iter lowest = b;
    if (b == e)
	return e;
    while (++b != e)
	if (*b < *lowest)
	    lowest = b;
    return lowest;
}

for the lexicographical compare, its giving me an error for the second line: no match for 'operator< '

Code:

template <class In>
bool my_lexicographic_compare(In b, In e, In b2, In e2)
{
    while (b != e)
	{
	    if (*b2 < b || b2 == e2)
		return false;
		else if (*b < *b2)
		    return true;
	    b++;
	    b2++;
	}
    return (b2 != e2);
}

Code:

template <class In>
In my_min_element(In b, In e)
{
    In lowest = b;
    if (b == e)
        return e;
    while (++b != e)
        if (*b < *lowest)
            lowest = b;
    return lowest;
}

template <class In>
bool my_lexicographic_compare(In b, In e, In b2, In e2)
{
    while (b != e)
    {
        if (*b2 < *b || b2 == e2)
            return false;
        else if (*b < *b2)
            return true;
        b++;
        b2++;
    }
    return (b2 != e2);
}