Removing a value from QList via if statement check

[ebsaith]

When a user clicks, the mouse position x & y value is stored in a QList<int>
User will be able to click several times

My problem is if a user clicks the same spot where he/she already clicked
that x & y value must be deleted from the array only.

This is so far what i got:

//In mouseMove function
        if(ev->button()==Qt::LeftButton)
        {
           x1 = ev->x();
           y1 = ev->y(); //x1,y1 are temp variables later in same function used to .append into array
...
}

//In mouseMove function
        if(ev->button()==Qt::LeftButton)
        {
           x1 = ev->x();
           y1 = ev->y(); //x1,y1 are temp variables later in same function used to .append into array
...
}

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RemoveValue function is:

void class::RemovePoint()
{
    int r = 0;
    do
    {
        //Only 1 Array stored in format x|y|x|y|x|y|x|y|x|y|...
        if(Array1[r] == x1 && Array1[r+1] == y1)
        {
            Array1.removeAt(r);
            Array1.removeAt(r);
        }
        r = r + 2; //Jumps to next x value
    }while(r < 50); lets say 25 points, hence x & y values = 50 array elements
}

void class::RemovePoint()
{
    int r = 0;
    do
    {
        //Only 1 Array stored in format x|y|x|y|x|y|x|y|x|y|...
        if(Array1[r] == x1 && Array1[r+1] == y1)
        {
            Array1.removeAt(r);
            Array1.removeAt(r);
        }
        r = r + 2; //Jumps to next x value
    }while(r < 50); lets say 25 points, hence x & y values = 50 array elements
}

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I am not worried about the display
Just need the array to be updated as it happens

Program compiles
when I test the same point
Program crashes
[Invalid parameter passing & Assert Failure :"index out of range"

Help Appreciated...Much
Thanks