Hi Gene,
I was thinking the same thing which you implemented in your first
snippet. But I tried it without using typedef. Following is my code:
#include stdio.h
#include malloc.h
int main()
{
int (*ptr)[4] ;
ptr = (int ((*)[4]))malloc(2*sizeof(int (*)[4]));
if (ptr) {
Here's my solution.
int** allocateMatrix(int m, int n)
{
int **rowList = (int**)malloc(sizeof(int)*m*n + sizeof(int*)*m);
int *colList = (int*)(rowList+m);
int i;
for(i=0; im; i++)
{
rowList[i] = colList+i*n;
}
return rowList;
}
And here's the main method to test/understand the
@sandeep sir: thnx... good 1 :)
On Sat, Jul 2, 2011 at 11:32 PM, Sandeep Jain sandeep6...@gmail.com wrote:
Here's my solution.
int** allocateMatrix(int m, int n)
{
int **rowList = (int**)malloc(sizeof(int)*m*n + sizeof(int*)*m);
int *colList = (int*)(rowList+m);
int i;
for(i=0; im;
Unfortunately this invokes undefined behavior, so it may not work for
all architectures and compilers. It relies on pointers to int having
the same alignment as int.
By far the best way to do this is use C99 features:
double (*a)[n_cols] = calloc(n_rows, sizeof *a);
If you don't have C99 and
do we need to add m in each a[i]?? shudnt it be a[i] = a+ n*i?? i think i m
doing a silly mistake.. bt plz tell me..
On Thu, Jun 30, 2011 at 7:41 AM, Dave dave_and_da...@juno.com wrote:
@Rizwan: Not completely. What if ROW in your code is a variable (not a
constant) that is not known until run
#includestdio.h
int main()
{
int i,j;
int ct=0;
int *a[3];
for( i=0;i3;i++)
{
a[i]=(int **)malloc(sizeof(int)*4);
for(i=0;i3;i++){
for(j=0;j4;j++)
a[i][j]=ct++;
printf(%d,a[i][j]);
}
}
}
On Sat, Jul 2, 2011 at 12:13 AM, Anika Jain anika.jai...@gmail.com wrote:
do we need to add m in each a[i]??
@saurabh.. No man.. it involves variable number of calls.. even if its
present only once in code.
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#includestdio.h
int main()
{
int i,j;
int ct=0;
int *a[3];
for( i=0;i3;i++)
{
a[i]=(int **)malloc(sizeof(int)*4);
}
for(i=0;i3;i++){
for(j=0;j4;j++)
a[i][j]=ct++;
printf(%d,a[i][j]);
}
On Sat, Jul 2, 2011 at 2:27 AM, sravanreddy001 sravanreddy...@gmail.comwrote:
@saurabh.. No man.. it involves
Apoorve: No.
Dave
On Jun 29, 2:34 pm, Apoorve Mohan apoorvemo...@gmail.com wrote:
@piyush: only one call to malloc...ur sol has 2
On Thu, Jun 30, 2011 at 12:58 AM, Piyush Sinha
ecstasy.piy...@gmail.comwrote:
int **p;
p = (int **)malloc(sizeof(int *)*row);
for(i = 0;irow;i++)
@Rizwan: Not completely. What if ROW in your code is a variable (not a
constant) that is not known until run time? Then you need to
dynamically allocate space for your arr2D as well. So, contradicting
my earlier No response, maybe something like this would work to
allocate an array a with m rows
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