commit 36ea6d6c6b8f484e4b4c21bfcbeecbc821658fdb
parent c982a96b1332bb740067be737e7ec8f6a0b43262
Author: Dimitrije Dobrota <mail@dimitrijedobrota.com>
Date: Tue, 16 Apr 2024 20:06:46 +0200
Streamline get_naked functions
Diffstat:
| M | main.cpp | | | 161 | +++++++++++++++++++++++++------------------------------------------------------ |
1 file changed, 51 insertions(+), 110 deletions(-)
diff --git a/main.cpp b/main.cpp
@@ -125,10 +125,6 @@ class Ref {
return res;
}
- auto get_hidden_pairs() const { return get_hidden(2); }
- auto get_hidden_triplets() const { return get_hidden(3); }
- auto get_hidden_quads() const { return get_hidden(4); }
-
auto get_naked_singles() const {
changes_t res;
@@ -143,111 +139,13 @@ class Ref {
return res;
}
- auto get_naked_pairs() const {
- changes_t res;
-
- for (uint8_t i = 0; i < 9; i++) {
- if (std::popcount(value[i]) != 2) continue;
- if (seen_naked_pair & (1ul << i)) continue;
- for (uint8_t j = i + 1; j < 9; j++) {
- if (value[i] != value[j]) continue;
- if (seen_naked_pair & (1ul << j)) continue;
-
- seen_naked_pair |= 1ul << i;
- seen_naked_pair |= 1ul << j;
-
- uint16_t val = value[i];
- while (val) {
- const uint8_t idx = std::countr_zero(val);
- for (uint8_t pos = 0; pos < 9; pos++) {
- if (pos == i || pos == j) continue;
- res.emplace_back(pos, idx);
- }
- val ^= 1ull << idx;
- }
- }
- }
-
- return res;
- }
-
- auto get_naked_triplets() const {
- changes_t res;
-
- 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;
-
- seen_naked_triplet |= 1ul << i;
- seen_naked_triplet |= 1ul << j;
- seen_naked_triplet |= 1ul << k;
-
- while (val) {
- const uint8_t idx = std::countr_zero(val);
- for (uint8_t pos = 0; pos < 9; pos++) {
- if (pos == i || pos == j || pos == k) continue;
- res.emplace_back(pos, idx);
- }
- val ^= 1ull << idx;
- }
- }
- }
- }
- return res;
- }
-
- auto get_naked_quads() const {
- changes_t res;
+ auto get_hidden_pairs() const { return get_hidden(2); }
+ auto get_hidden_triplets() const { return get_hidden(3); }
+ auto get_hidden_quads() const { return get_hidden(4); }
- 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);
- for (uint8_t pos = 0; pos < 9; pos++) {
- if (pos == i || pos == j || pos == k || pos == l) continue;
- res.emplace_back(pos, idx);
- }
- val ^= 1ull << idx;
- }
- }
- }
- }
- }
- return res;
- }
+ auto get_naked_pairs() const { return get_naked(2); }
+ auto get_naked_triplets() const { return get_naked(3); }
+ auto get_naked_quads() const { return get_naked(4); }
private:
changes_t get_hidden(int number) const {
@@ -261,7 +159,7 @@ class Ref {
bool get_hidden(changes_t &res, uint8_t og, uint8_t number, uint8_t first, uint16_t val,
uint16_t mask) const {
if (number != 0) {
- for (int i = first; i < 9; i++) {
+ for (uint8_t i = first; i < 9; i++) {
if (std::popcount(ref[i]) < 2) continue;
if (seen_hidden[og] & (1ul << i)) continue;
@@ -295,6 +193,49 @@ class Ref {
return true;
}
+ changes_t get_naked(int number) const {
+ assert(number > 1 && number <= 4);
+
+ changes_t res;
+ get_naked(res, number, number, 0, 0);
+ return res;
+ }
+
+ bool get_naked(changes_t &res, uint8_t og, uint8_t number, uint8_t first, uint16_t val) const {
+ static uint8_t seen[4] = {0};
+
+ if (number != 0) {
+ for (uint8_t i = first; i < 9; i++) {
+ if (this->res[i]) continue;
+ if (number == og && seen_naked[og] & (1ul << i)) continue;
+
+ seen[og - number] = i;
+ bool used = get_naked(res, og, number - 1, i + 1, val | value[i]);
+ if (!used) continue;
+
+ if (number == og) seen_naked[og] |= 1ul << i;
+ if (number != og) return true;
+ }
+
+ return false;
+ }
+
+ if (std::popcount(val) != og) return false;
+
+ while (val) {
+ const uint8_t idx = std::countr_zero(val);
+ for (uint8_t pos = 0, i; pos < 9; pos++) {
+ for (i = 0; i < og; i++) {
+ if (pos == seen[i]) break;
+ }
+ if (i == og) res.emplace_back(pos, idx);
+ }
+ val ^= 1ull << idx;
+ }
+
+ return true;
+ }
+
static constexpr const std::int64_t mask_field = (1 << 9) - 1;
static constexpr const std::int64_t mask_value = 0x201008040201;
@@ -307,8 +248,8 @@ class Ref {
uint16_t res[9] = {0};
mutable uint16_t seen_hidden[4] = {0};
+ mutable uint16_t seen_naked[4] = {0};
- mutable uint16_t seen_naked_pair = 0, seen_naked_triplet = 0, seen_naked_quad = 0;
mutable uint16_t seen_point_row = 0, seen_point_col = 0;
};
