Swap Through Qualifiers

Implement two swap variants that demonstrate the const contracts: ``c void swap(int *x, int *y); /* ordinary swap */ int swap_if_sorted(const int **px, const int **py); /* if **px > **py, swap the POINTERS so *px ends up pointing at the smaller value; returns 1 if swapped */ ` swap_if_sorted` takes pointers-to-pointers-to-const: it may move which pointer points where, but never write through to the ints.

Difficulty: intermediate