Interview Question : Trim multiple consecutive spaces from a string

Question

This is an interview question Looking for best optimal solution to trim multiple spaces from a string. This operation should be in-place operation.

input  =          


        

Answer 1

I'd just go with this:

int main(int argc, char* argv[])
{
    char *f, *b, arr[] = "  This        is    a test.                ";
    f = b = arr;

    if (f) do
    {
        while(*f == ' ' && *(f+1) == ' ') f++;
    } while (*b++ = *f++);

    printf("%s", arr);

    return 0;
}