C++ - Ordered ArrayList - c++

Question

I have an ordered arrayList. Where elements are to be ordered in 1,2,3,4,5,6.
At the moment the push function is not working. It will insert an element, but there is a problem which i cannot figure out. The push will work once you insert an incremented number... So like 1,2,3,4,5 but will not work once i insert like this 5,2,4,3,2,1.
Can anyone help me with this?
Here is my code:
Initialisation
template <class Datatype>
//--------------------------------------------------------------------------------------------
// Class: OrderedArray.
//--------------------------------------------------------------------------------------------
class OrderedArray
{
//--------------------------------------------------------------------------------------------
// Member Variables.
//--------------------------------------------------------------------------------------------
private:
Datatype* m_array;
int size;
int g_size;
int num_elements;
//---------------------------------------------------------------------------------------
// Name: Print Function:
// Description: To print out all elemenst in the Array.
//---------------------------------------------------------------------------------------
void print()
{
for(int i=0;i< size;i++)
{
cout << "Position: " <<m_array[i]<<endl;
}
}
//---------------------------------------------------------------------------------------
// Name: Resize Function:
// Description: To resize the Array.
//---------------------------------------------------------------------------------------
void Resize(int p_size)//resizes the array to the size of p_size
{
if(p_size < 0)//checks if new size is less than 0
{
cout << "ERROR! Size of an array can not be less than 0!" << endl;
}
else//else its ok to continue
{
Datatype* newArray = new Datatype[p_size];//creates a pointer newArray that points at a new array
if(newArray == 0)
return;
int min;
if(p_size < m_size)//checks the if the new array is smaller than the old one
min = p_size;
else//else its going to be bigger
min = m_size;
int index;
int temp = num_elements;//puts num_elements into a temporary variable called temp
num_elements = 0;//num_elements is set to 0
for(index = 0; index < min; index++)
{
newArray[index] = m_array[index];//places everything from the old array into the new array that will fit.
if(num_elements < temp)//if the num_elements is less than temp(the original num_elements)
{
num_elements++;//increment num_elements. This will keep incrementing to create the new num_elements based the number of elements cut off in the resize
}
}
m_size = p_size;//sets the old size to be equal to the new size
if(m_array != 0)
delete[] m_array;//deletes the old array
m_array = newArray;//makes m_array point at the new array
newArray = 0;//makes newArray a null pointer
}
}
//---------------------------------------------------------------------------------------
// Name: Push
// Description:
//---------------------------------------------------------------------------------------
void push(Datatype p_item)
{
if(num_elements == size)//checks if the array is full and needs to be resized
{
Resize(size + g_size);//calls the resize function
}
int pos = num_elements;
for(int x=0;x<num_elements;x++)
{
if(p_item < m_array[x])
pos=x;
break;
}
//loops through the array from high to low moving all values to the right
//to make space for the passed in value until it gets to the right place
for(int index = num_elements; index >= pos; index--)
{
m_array[index] = m_array[index-1];//moves the values to the right
}
m_array[pos] = p_item;//the passed in value is positioned into its ordered position
num_elements++;
cout<< "Num Elements " << num_elements;
cout<< "Size " <<size;
}

Answer 1

I think I found the beginning of the problem:
for(int x=0;x<num_elements;x++)
{
if(p_item < m_array[x])
pos=x;
}
your pos will always always be at the end of the array that way(assuming the array is properly sorted up to that point). add a break statement to let your loop know when it should stop assigning greater and greater values to pos
for(int x=0;x<num_elements;x++)
{
if(p_item < m_array[x])
{
pos=x;
break;
}
}
your code has some other issues too, for instance
for(int index = num_elements; index > pos; index--)
{
m_array[index] = m_array[index+1];//moves the values to the right
}
actually moves the values left. change the assignment to
for(int index = num_elements; index > pos; index--)
{
m_array[index] = m_array[index-1];//moves the values to the right
}