zakarya/puzzles
1
0
Fork 0
mirror of git://git.tartarus.org/simon/puzzles.git synced 2025-04-20 23:51:29 -07:00
Code Issues Packages Projects Releases Wiki Activity

Reorganise the dsf API into three kinds of dsf.

Browse Source 
This is preparing to separate out the auxiliary functionality, and
perhaps leave space for making more of it in future.

The previous name 'edsf' was too vague: the 'e' stood for 'extended',
and didn't say anything about _how_ it was extended. It's now called a
'flip dsf', since it tracks whether elements in the same class are
flipped relative to each other. More importantly, clients that are
going to use the flip tracking must say so when they allocate the dsf.

And Keen's need to track the minimal element of an equivalence class
is going to become a non-default feature, so there needs to be a new
kind of dsf that specially tracks those, and Keen will have to call it.

While I'm here, I've renamed the three dsf creation functions so that
they start with 'dsf_' like all the rest of the dsf API.
This commit is contained in:
Simon Tatham
2023-04-20 17:27:21 +01:00
parent 14e1e05510
commit c5e253a9f9
23 changed files with 131 additions and 119 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
dsf.c
View File

@ -34,7 +34,7 @@ void dsf_copy(DSF *to, DSF *from)
memcpy(to->p, from->p, to->size * sizeof(int));
}
DSF *snew_dsf(int size)
DSF *dsf_new(int size)
{
DSF *ret = snew(DSF);
ret->size = size;
@ -45,6 +45,9 @@ DSF *snew_dsf(int size)
return ret;
}
DSF *dsf_new_min(int size) { return dsf_new(size); }
DSF *dsf_new_flip(int size) { return dsf_new(size); }
void dsf_free(DSF *dsf)
{
if (dsf) {
@ -55,24 +58,29 @@ void dsf_free(DSF *dsf)
int dsf_canonify(DSF *dsf, int index)
{
return edsf_canonify(dsf, index, NULL);
return dsf_canonify_flip(dsf, index, NULL);
}
int dsf_minimal(DSF *dsf, int index)
{
return dsf_canonify_flip(dsf, index, NULL);
}
bool dsf_equivalent(DSF *dsf, int i1, int i2)
{
return edsf_canonify(dsf, i1, NULL) == edsf_canonify(dsf, i2, NULL);
return dsf_canonify(dsf, i1) == dsf_canonify(dsf, i2);
}
void dsf_merge(DSF *dsf, int v1, int v2)
{
edsf_merge(dsf, v1, v2, false);
dsf_merge_flip(dsf, v1, v2, false);
}
int dsf_size(DSF *dsf, int index) {
return dsf->p[dsf_canonify(dsf, index)] >> 2;
}
int edsf_canonify(DSF *dsf, int index, bool *inverse_return)
int dsf_canonify_flip(DSF *dsf, int index, bool *inverse_return)
{
int start_index = index, canonical_index;
bool inverse = false;
@ -107,17 +115,17 @@ int edsf_canonify(DSF *dsf, int index, bool *inverse_return)
return index;
}
void edsf_merge(DSF *dsf, int v1, int v2, bool inverse)
void dsf_merge_flip(DSF *dsf, int v1, int v2, bool inverse)
{
bool i1, i2;
assert(0 <= v1 && v1 < dsf->size && "Overrun in edsf_merge");
assert(0 <= v2 && v2 < dsf->size && "Overrun in edsf_merge");
v1 = edsf_canonify(dsf, v1, &i1);
v1 = dsf_canonify_flip(dsf, v1, &i1);
assert(dsf->p[v1] & 2);
inverse ^= i1;
v2 = edsf_canonify(dsf, v2, &i2);
v2 = dsf_canonify_flip(dsf, v2, &i2);
assert(dsf->p[v2] & 2);
inverse ^= i2;
@ -147,7 +155,7 @@ void edsf_merge(DSF *dsf, int v1, int v2, bool inverse)
dsf->p[v2] = (v1 << 2) | inverse;
}
v2 = edsf_canonify(dsf, v2, &i2);
v2 = dsf_canonify_flip(dsf, v2, &i2);
assert(v2 == v1);
assert(i2 == inverse);
}