Remove white space at the end of the output in C

Question

The following code is for printing the elements of a matrix in spiral order. The program works fine. The problem, however, is that the online compiler against which I\'m checkin

Answer 1

Looking at your code, this for (the first one in the while loop):

for (i = l; i < n; ++i)
    printf("%d ", a[k][i]);

will always be executed at least ones (because l, coming from the while's condition).

Then you can just do the following:

• always add the space in front of the number
• add a single if check just for this very first for-loop (use some bool flag).

For example, something like:

bool first = true;
while (k < m && l < n)
{
    for (i = l; i < n; ++i)
    {
        if( ! first )
        {
            printf(" %d", a[k][i]);
        }
        else
        {
            printf("%d", a[k][i]);
            first = false;
        }
    }
    // ....
}

This will be rather efficient and short solution - the if is in just one loop and the flag will be true just once (will avoid cache misses).