Thread: how to use memset for int?

Code:

int arr[512];
int val = 5;

/*
how i use memset() to set all the elements of arr[] to val?
 */

I dont think you can with memset. You can set each BYTE of that block of memory to 5 but not each element (which is made up of 4 bytes)

Code:

for(unsigned int i = 0; i < sizeof(arr) / sizeof(*arr); ++i)
  arr[i] = val;

yeah! i had to do the obvious:

Code:

void fill_grid(int* grid, int nr, int nc, int val)
{
	int i;
	for (i=0; i<(nr*nc); i++)
	{
		grid[i] = val;
	}
}

but since assembly has the instructions for byte,word and dword:
stodb, stosw, stosd
and memset works very fast, i thougt may be there is something to set ints as well!

Originally Posted by manav

yeah! i had to do the obvious:

Code:

void fill_grid(int* grid, int nr, int nc, int val)
{
	int i;
	for (i=0; i<(nr*nc); i++)
	{
		grid[i] = val;
	}
}

but since assembly has the instructions for byte,word and dword:
stodb, stosw, stosd
and memset works very fast, i thougt may be there is something to set ints as well!

Code:

    int* maxPtr = arr + 512;
    int* ptr = arr;
    while(ptr < maxPtr)
        *ptr++ = val;

Thats probably the fastest way.