Convert a two-dimensional array to a one demensional array

Well the title pretty much explains itself...anyone know how to do this?

Yes. Pointer arithmetic and/or cast :p

so if i had an array for example power[8][7], i would cast it how?

power1D[56] == power2D[8][7]

Of course you can't assign arrays-as-a-whole. But you could do int *power1D=power2D[8][7], and pretend that power1D has 56 elements.

so it must have that pointer

You could use a real array if you want, instead of a pointer. But you'd have to use a big ol' for-loop to get all the numbers in the new array.

ok ill go with the pointer

As long as you access the 2D array elements in their proper storage order you can use either a pointer with an offset or a subscripted array.
The thing to remember is to walk along the 2D array correctly knowing that the rightmost subscript varies fastest.

so does this work NROWS being 8 and NCOLS being 7

Code:

---

int i, j, k;
int power1d[56];

for(i = 0; i<NROWS; i++)
{
for(j=0; j<NCOLS; j++)
{
for(k=0; k <56; k++)
power1d = power[i][j];
}}

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Quote:

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Originally Posted by belkins

so does this work NROWS being 8 and NCOLS being 7

Code:

---

int i, j, k;
int power1d[56];

for(i = 0; i<NROWS; i++)
{
for(j=0; j<NCOLS; j++)
{
for(k=0; k <56; k++)
power1d = power[i][j];
}}

---

---

No. You can never assign to the name of an array. Fortunately, you don't want to assign the name of an array, but to a particular slot in the array.

does another array need to be declared?

Quote:

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Originally Posted by belkins

does another array need to be declared?

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Of course not.

do i declare the 2-d array as one-d then

Quote:

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Originally Posted by belkins

do i declare the 2-d array as one-d then

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Well, wait. I thought you meant another another array. The one one-d array you already have is fine. But you have to assign to array[something], not just array.

right it should be

Code:

---

fint i, j, k;
int power1d[56];

for(i = 0; i<NROWS; i++)
{
for(j=0; j<NCOLS; j++)
{
for(k=0; k <56; k++)
power1d[k] = power[i][j];
}}

---

i fixed the power1d

Closer. You just have to decide what k is going to be. Currently you are assigning each element of power into every element of power1d, which means only the last element is the one you get kept. You're already in the for loop, so you're looking at one specific element of the power array -- now where does that one specific element need to go?

Yea i knew something was wrong because when i printed it out it was a mess, so does k need to be an outside loop?

k shouldn't be a loop at all. k needs to be computed based on i and j.

so k should be
k=(i +1) *(j+1) - 1
????

i dont think this is the right equation? it works for the first seven then messes up on the index, but the value of the index is correct, do you know of an equation that would fix this?

figured it out
k=(i*7)+j;

Quote:

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Originally Posted by belkins

figured it out
k=(i*7)+j;

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bingo!

Look at code that I have posted. I have given many examples of how to do this.