Qsort array of strings in descending order

Question

To sort an array of strings in ascending order, I use:

int cmp(const void *p, const void *q) {
     char* const *pp = p;
     char* const *qq = q;
     return strcmp(*pp, *qq);
}

This will be then implemented into a qsort like so:

qsort(a, sizeof(a)(sizeof(a[0]), sizeof(a[0]), cmp);

How do you sort it in descending order?

Answer 1

One quick and easy way to do this is to multiply the result of strcmp() by -1 before returning it.

int cmp(const void *p, const void *q) {
     char* const *pp = p;
     char* const *qq = q;
     return -strcmp(*pp, *qq);
}

Answer 2

只需返回否定结果（ -strcmp(*pp, *qq) ）。