Pointers and arrays

I am trying to create a dynamic array - one that increases in element size when I encounter a new thing to be added. It copies over the old elements in the new array, but I find that the returning function does not seem to actually return the correct array. Can you help? The code is listed below:

#include <stdio.h>



void arraycopy(int oldarray[], int newarray[], int index);
void NNListBuild(int lipidIndex, int *NNInput, int *NNList, int arrayindex);

void arraycopy(int oldarray[], int newarray[], int index)
{

int i;
for (i=0;i<index;i++)
{
newarray[i] = oldarray[i];
//printf("copying: %d\n", newarray[i]);
}


}


void NNListBuild(int lipidIndex,int *NNInput, int *NNList, int arrayindex)
{

int *newarray = new int[arrayindex+1];
arraycopy(NNInput, newarray, arrayindex);

NNInput = newarray;
NNInput[arrayindex] = 110;

int i;
for (i=0;i<arrayindex+1;i++)
{

//printf("copying: %d\n", NNInput[i]);
}


NNList = &NNInput[0];

for (i=0;i<arrayindex+1;i++)
{

printf("after copying: %d\n", NNList[i]);
}

//delete [] newarray;

}



int main(void)
{
int arrayindex;
arrayindex = 4;
int *NNList = new int[arrayindex];
int *NNOutput;
NNList[0] = 1;
NNList[1] = 2;
NNList[2] = 3;
NNList[3] = 4;
NNListBuild(7,NNList,NNOutput,arrayindex);





//arraycopy(oldarray,newarray,arrayindex);

int i;
for (i=0;i<arrayindex+1;i++)
{

printf("final output: %d\n", NNOutput[i]);
}


delete [] NNList;
//delete [] newarray;
printf("hello");
return 0;
}

void NNListBuild(int lipidIndex, int *NNInput, int *&NNList, int arrayindex)
{
NNList = new int[arrayindex+1];
arraycopy(NNInput, NNList, arrayindex);
NNList[arrayindex] = 110;
}

int main(void)
{
int arrayindex=4;
int *NNList = new int[arrayindex];
int *NNOutput = NULL;
NNList[0] = 1;
NNList[1] = 2;
NNList[2] = 3;
NNList[3] = 4;
NNListBuild(7,NNList,NNOutput,arrayindex);
delete [] NNList;
delete[] NNOutput;
}

Thanks for that - however it does not seem to work - the returning elemnts of the Output array cannot be displayed leading to a segmentation fault. The code is as you sugggsted.

I do not receive no errors with this code.