doasku

commit 80ab88e90146b327b622201960bae4414106d2e0
parent 1f999f0dafb7e5b013add6f89e89a1fb28a60d02
Author: Dimitrije Dobrota <mail@dimitrijedobrota.com>
Date:   Sun,  7 Apr 2024 21:32:34 +0200

Add check for naked triplets

Diffstat:
M
main.cpp
 | 
71
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 71 insertions(+), 0 deletions(-)
diff --git a/main.cpp b/main.cpp
@@ -102,6 +102,35 @@ class Ref {
         return res;
     }
 
+    auto get_naked_triplets() const {
+        std::vector<std::tuple<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_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);
+                        res.emplace_back(idx, i, j, k);
+                        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};
@@ -111,6 +140,7 @@ class Ref {
     uint16_t res[9] = {0};
 
     mutable uint16_t seen_naked_pair = 0;
+    mutable uint16_t seen_naked_triplet = 0;
 };
 
 class Grid {
@@ -180,6 +210,19 @@ class Grid {
 
                     changes++;
                 }
+
+                const auto nt = subgrids[subgrid].get_naked_triplets();
+                for (const auto [val, f1, f2, f3] : nt) {
+                    std::cout << "naked triplets: " << (int)subgrid << " " << (int)f1 << " " << (int)f2 << " "
+                              << (int)f3 << " " << (int)val << std::endl;
+
+                    for (uint8_t field = 0; field < 9; field++) {
+                        if (field == f1 || field == f2 || field == f3) continue;
+                        _clear(subgrid, field, val);
+                    }
+
+                    changes++;
+                }
             }
 
             for (uint8_t row = 0; row < 9; row++) {
@@ -207,6 +250,20 @@ class Grid {
 
                     changes++;
                 }
+
+                const auto nt = rows[row].get_naked_triplets();
+                for (const auto [val, c1, c2, c3] : nt) {
+                    std::cout << "naked triplets row: " << (int)row << " " << (int)c1 << " " << (int)c2 << " "
+                              << (int)c3 << " " << (int)val << std::endl;
+
+                    for (uint8_t col = 0; col < 9; col++) {
+                        if (col == c1 || col == c2 || col == c3) continue;
+                        const auto [subgrid, field] = row_col_t(row, col).relative();
+                        _clear(subgrid, field, val);
+                    }
+
+                    changes++;
+                }
             }
 
             for (uint8_t col = 0; col < 9; col++) {
@@ -234,6 +291,20 @@ class Grid {
 
                     changes++;
                 }
+
+                const auto nt = cols[col].get_naked_triplets();
+                for (const auto [val, r1, r2, r3] : nt) {
+                    std::cout << "naked triplets col: " << (int)col << " " << (int)r1 << " " << (int)r2 << " "
+                              << (int)r3 << " " << (int)val << std::endl;
+
+                    for (uint8_t row = 0; row < 9; row++) {
+                        if (row == r1 || row == r2 || row == r3) continue;
+                        const auto [subgrid, field] = row_col_t(row, col).relative();
+                        _clear(subgrid, field, val);
+                    }
+
+                    changes++;
+                }
             }
 
             if (changes) iter++;