Declarations of functions associated with group_F.
Version of Monday 23 September 2024.

This declaration:

    /* F1 */ struct perm_bool;       

is for this definition:

    struct permzbi::perm_bool {
        permzbi p;
        bool b;
    };

When a perm_bool is returned from a function, its members are p containing the next or previous permutation; and b containing false if the result is the first permutation (in the case of next_perm_) or the last (in the case of prev_perm_). In other words, b is false if the calculation had to "wrap around". Otherwise, b is true.

The function names with _modify and _create involve the same considerations as those in group_E. Also, the begin and end parameters have the same significance.

The next four functions presume lexicographical sequence, and are little more than wrappers for the Standard Library's next_permutation and prev_permutation.

    /* F1 */ bool      next_perm_lex_modify (int begin = 0, int end = −1);
    /* F1 */ perm_bool next_perm_lex_create (int begin = 0, int end = −1) const;
    /* F1 */ bool      prev_perm_lex_modify (int begin = 0, int end = −1);
    /* F1 */ perm_bool prev_perm_lex_create (int begin = 0, int end = −1) const;

    /* F2 */ bool      next_perm_SJT_modify (int begin = 0, int end = −1);
    /* F2 */ perm_bool next_perm_SJT_create (int begin = 0, int end = −1) const;
    /* F2 */ bool      prev_perm_SJT_modify (int begin = 0, int end = −1);
    /* F2 */ perm_bool prev_perm_SJT_create (int begin = 0, int end = −1) const;