Thread: Assigning Multiple Values to Array/ Vector

Hi,

Say if, like in the following example, you want to check if a variable has one of two sets of values. Is there a way of doing this, but without writing out "a1 = 12, a2 = ...." etc.?

I'm thinking you could do it with two arrays- one for the first set of values then another for the second set. Then you would just assign one of those arrays to a vector and check if c is any of the values in the vector. But I'm wondering, would it be possible to do this with using only 1 array or vector? Something like:

Code:

vector<int> v1;
if (b == 1) 
    v1 = {12, 15, 11, 17, 18 };
if (b == 2) 
    v1 = {21, 25, 27, 26, 28 };

Or is there any other more efficient way to do the program?

Thanks.

Code:

#include <iostream>
using namespace std;

int main()
{
    int a1, a2, a3, a4, a5, b, c;
    cout << "press 1 for set 1 and 2 for set 2";
    cin >> b;
    if (b == 1)
    {
        a1 = 12;
        a2 = 15;
        a3 = 11;
        a4 = 17;
        a5 = 18;
    }
    else if (b == 2)
    {
        a1 = 21;
        a2 = 25;
        a3 = 27;
        a4 = 26;
        a5 = 28;
    }
    cout << "Enter a number to check if it's in the set selected";
    cin >> c;
    if (c == a1 || c == a2 || c == a3 || c == a4 || c == a5)
        cout << "You entered a value that is in set " << b;
    else
        cout << "Number not in set " << b;
}

Your idea of using a vector is a good one. You can then just use the find() function in the vector to see if the number is in your set.

You may want to consider doing something like:

Code:

vector<int> set1;
vector<int> set2;
// fill vectors with set data

cin >> b;

// Assign chosenSet to the set the user selected.  I didn't do error checking to see if b is within bounds (not ideal)
vector<int>& chosenSet = (b == 1) ? set1 : set2;

// Now check if the number the user entered is in the chosenSet vector

Interesting. I've never seen ? and : used like that before, but I looked them up and they seem useful. Thanks for the example.