Question

I have 2 arrays called xVal, and yVal.

I’m using these arrays as coords. What I want to do is to make sure that the array doesn’t contain 2 identical sets of coords.

Lets say my arrays looks like this:

int xVal[4] = {1,1,3,4};
int yVal[4] = {1,1,5,4};

Here I want to find the match between xVal[0] yVal[0] and xVal[1] yVal[1] as 2 identical sets of coords called 1,1.

I have tried some different things with a forLoop, but I cant make it work as intended.

Answer 1

You can do it with two for loops:

int MAX=4; //number of elements in array
for (int i=0; i<MAX; i++)
{
    for (int j=i+1; j<MAX; j++)
    {
        if (xVal[i]==xVal[j] && yVal[i]==yVal[j])
        {
            //DUPLICATE ELEMENT at xVal[j], yVal[j]. Here you implement what
            //you want (maybe just set them to -1, or delete them and move everything
            //one position back)
        }
    }
}

Small explanation: first variable i get value 0. Than you loop j over all possible numbers. That way you compare xVal[0] and yVal[0] with all other values. j starts at i+1 because you don’t need to compare values before i (they have already been compared).

Edit – you should consider writing small class that will represent a point, or at least structure, and using std::vector instead of arrays (it’s easier to delete an element in the middle). That should make your life easier 🙂