doasku

Human-like solver for sudoku
git clone git://git.dimitrijedobrota.com/doasku.git
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commit234d12dba299bd4c1b0f48d58f44f7082569d00f
parent80ab88e90146b327b622201960bae4414106d2e0
authorDimitrije Dobrota <mail@dimitrijedobrota.com>
dateSun, 7 Apr 2024 19:49:40 +0200

Add check for naked quads

Diffstat:
Mmain.cpp|+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 files changed, 83 insertions(+), 0 deletions(-)

diff --git a/main.cpp b/main.cpp

@@ -107,12 +107,15 @@ class Ref {

for (uint8_t i = 0; i < 9; i++) {
if (this->res[i]) continue;
if (seen_naked_triplet & (1ul << i)) continue;
for (uint8_t j = i + 1; j < 9; j++) {
if (this->res[j]) continue;
if (seen_naked_triplet & (1ul << j)) continue;
for (uint8_t k = j + 1; k < 9; k++) {
if (this->res[k]) continue;
if (seen_naked_triplet & (1ul << k)) continue;
uint16_t val = value[i] | value[j] | value[k];
if (std::popcount(val) != 3) continue;

@@ -131,6 +134,44 @@ class Ref {

return res;
}
auto get_naked_quads() const {
std::vector<std::tuple<uint8_t, uint8_t, uint8_t, uint8_t, uint8_t>> res;
for (uint8_t i = 0; i < 9; i++) {
if (this->res[i]) continue;
if (seen_naked_quad & (1ul << i)) continue;
for (uint8_t j = i + 1; j < 9; j++) {
if (this->res[j]) continue;
if (seen_naked_quad & (1ul << j)) continue;
for (uint8_t k = j + 1; k < 9; k++) {
if (this->res[k]) continue;
if (seen_naked_quad & (1ul << k)) continue;
for (uint8_t l = k + 1; l < 9; l++) {
if (this->res[l]) continue;
if (seen_naked_quad & (1ul << l)) continue;
uint16_t val = value[i] | value[j] | value[k] | value[l];
if (std::popcount(val) != 4) continue;
seen_naked_quad |= 1ul << i;
seen_naked_quad |= 1ul << j;
seen_naked_quad |= 1ul << k;
seen_naked_quad |= 1ul << l;
while (val) {
const uint8_t idx = std::countr_zero(val);
res.emplace_back(idx, i, j, k, l);
val ^= 1ull << idx;
}
}
}
}
}
return res;
}
private:
uint16_t value[9] = {mask_field, mask_field, mask_field, mask_field, mask_field,
mask_field, mask_field, mask_field, mask_field};

@@ -141,6 +182,7 @@ class Ref {

mutable uint16_t seen_naked_pair = 0;
mutable uint16_t seen_naked_triplet = 0;
mutable uint16_t seen_naked_quad = 0;
};
class Grid {

@@ -223,6 +265,19 @@ class Grid {

changes++;
}
const auto nq = subgrids[subgrid].get_naked_quads();
for (const auto [val, f1, f2, f3, f4] : nq) {
std::cout << "naked quads: " << (int)subgrid << " " << (int)f1 << " " << (int)f2 << " "
<< (int)f3 << " " << (int)f4 << " " << (int)val << std::endl;
for (uint8_t field = 0; field < 9; field++) {
if (field == f1 || field == f2 || field == f3 || field == f4) continue;
_clear(subgrid, field, val);
}
changes++;
}
}
for (uint8_t row = 0; row < 9; row++) {

@@ -264,6 +319,20 @@ class Grid {

changes++;
}
const auto nq = rows[row].get_naked_quads();
for (const auto [val, c1, c2, c3, c4] : nq) {
std::cout << "naked quad row: " << (int)row << " " << (int)c1 << " " << (int)c2 << " "
<< (int)c3 << " " << (int)c4 << " " << (int)val << std::endl;
for (uint8_t col = 0; col < 9; col++) {
if (col == c1 || col == c2 || col == c3 || col == c4) continue;
const auto [subgrid, field] = row_col_t(row, col).relative();
_clear(subgrid, field, val);
}
changes++;
}
}
for (uint8_t col = 0; col < 9; col++) {

@@ -305,6 +374,20 @@ class Grid {

changes++;
}
const auto nq = cols[col].get_naked_quads();
for (const auto [val, r1, r2, r3, r4] : nq) {
std::cout << "naked quad col: " << (int)col << " " << (int)r1 << " " << (int)r2 << " "
<< (int)r3 << " " << (int)r4 << " " << (int)val << std::endl;
for (uint8_t row = 0; row < 9; row++) {
if (row == r1 || row == r2 || row == r3 || row == r4) continue;
const auto [subgrid, field] = row_col_t(row, col).relative();
_clear(subgrid, field, val);
}
changes++;
}
}
if (changes) iter++;