Party Invitation

Question

The problem that I am working on right now is here, but I am of course not looking for the complete answer to this homework problem. All I am asking for is the steps in the final parts of the question. This is what I have so far:

int main()
{
    cout << "Please enter the number of guests attending your party: ";
    int k;
    cin >> k;
    cout << "Please enter the number of rounds of removal you'd like to perform: ";
    int m;
    cin >> m;
    for (int i = 1; i <= m; i++) {
        cout << "Please enter the multiple at which you'd like the removal to be at for round " << i << ": ";
            int r;
            cin >> r;
                if (k % r == 0) {
                    k - r;
                }
                cout << k << endl;
    }
    system("pause");
}

This is all so confusing to me, and I truly have no idea where to turn to get answers. It seems like I'd need an array to solve this, but arrays in C++ cannot be variable, and the array length would be k, a variable input. Any help would be very appreciated.

You need to make your question more explicit (what are "steps in the final parts of the question?"). Explain your problem better without relying on external links. — Ivan Aksamentov - Drop, Jan 21 '16 at 04:47
"arrays in C++ cannot be variable" Variable size? Well, true and false at the same time. I think that before proceeding further to any C++ you should first work out some good book: [The Definitive C++ Book Guide and List](http://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list) — Ivan Aksamentov - Drop, Jan 21 '16 at 04:49
I know that the output is 1,3,7,9, if the input is 10,2,2,3, but I can't find a way to get to those numbers with that input. I usually end up with 10,10, or just a singular 7. I think that I have the initialization down pat, and now it's just formulas & loops. This is where I'm getting caught up. Also, to everyone responding telling me to use vectors or lists, this is homework for a classroom that didn't teach that. I don't think it would be accepted if I went beyond for/while loops, if statements, basic arrays, etc. — Owen Pauli, Jan 21 '16 at 05:19

score 1 · Answer 1 · edited May 23 '17 at 11:52

1

I've read that question. you need a dynamic list like Linked list because you need to put and remove different items from different index so using arrays will be difficult.

Try to use std::vector or std::list, you can add or remove any any of list

#include <list>
std::list<int> mylist;

How can you add and remove values from list, check this link http://en.cppreference.com/w/cpp/container/list

For using your own Linklist, check this link How could i create a list in c++?

edited May 23 '17 at 11:52

Community

1
1

answered Jan 21 '16 at 04:51

Muhammad Zeeshan

470
7
24

Do I **need** a dynamic list, or is it suggested? Considering that this is a homework problem for a class that never went beyond basic arrays, variables, for/while loops, if statements, and the like, I don't think it'd be appropriate to hand in work made with something beyond the curriculum. – Owen Pauli Jan 21 '16 at 05:20

score 0 · Answer 2 · answered Jan 21 '16 at 05:48

According to your question an std::vector will be the best choice because it is a combination of an array & linked list in raw terms or we can simply say it's a dynamic array.

However as you mentioned n your comment that you haven't been taught anything other than basic arrays & want a solution within whatever you have learnt, then you have to take an array. Now the problem is that arrays are static & you cannot delete elements from it. So all you can do is to keep a counter that will take care of the number of elements in it.

// array insert and delete
#include <iostream>
using namespace std;

void see_array (int a[], int f, int b)
{
    for (int i=f; i<b; ++i)
    cout << a[i] << ' ';
    cout << '\n';
}

int get_pos (int a[], int f, int b, int num)
{
    for (int i=f; i<b; ++i)
    {
        if (a[i] == num)
        return i;
    }
    return -1;  // if search is unsuccessful
}

int main()
{
    int a[] = {1,2,3,4,5,6,7,8,9,10};
    int front = 0, back = 10; // as we have 10 elements

    // delete last element
    --back;
    see_array(a, front, back);

    // delete first element
    ++front;
    see_array(a, front, back);

    // delete element from middle say 6
    int pos = get_pos(a, front, back, 6);
    if (pos != -1)
    {
        for (int i = pos; i<back; ++i)  // shift elements towards left
        {
            a[i] = a[i+1];
        }
        --back;  // decrease size of the array
        see_array(a, front, back);
    }

    return 0;
}
/* Output :-
1 2 3 4 5 6 7 8 9
2 3 4 5 6 7 8 9
2 3 4 5 7 8 9
*/

I hope the above program is of some help to you !!! Good luck !!!

Party Invitation

2 Answers2