2023 day 14: skip Grid bounds checking

C++23 multidimensional subscripting would be nice here.
yut23 · Mar 22, 2024 · c06933a · c06933a
1 parent 6e1b562
commit c06933a
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Showing 2 changed files with 10 additions and 4 deletions.
diff --git a/2023/src/day14.hpp b/2023/src/day14.hpp
@@ -48,7 +48,7 @@ void Platform::transpose() {
     const int n = rocks.width;
     for (int y = 0; y < n; ++y) {
         for (int x = 0; x < y; ++x) {
-            std::swap(rocks.at(x, y), rocks.at(y, x));
+            std::swap(rocks.at_unchecked(x, y), rocks.at_unchecked(y, x));
         }
     }
 }
@@ -58,7 +58,7 @@ void Platform::flip_rows() {
     for (int y = 0; y < n; ++y) {
         for (int x = 0; x < n / 2; ++x) {
             const int z = n - x - 1;
-            std::swap(rocks.at(x, y), rocks.at(z, y));
+            std::swap(rocks.at_unchecked(x, y), rocks.at_unchecked(z, y));
         }
     }
 }
@@ -68,7 +68,7 @@ void Platform::flip_columns() {
     for (int x = 0; x < n; ++x) {
         for (int y = 0; y < n / 2; ++y) {
             const int z = n - y - 1;
-            std::swap(rocks.at(x, y), rocks.at(x, z));
+            std::swap(rocks.at_unchecked(x, y), rocks.at_unchecked(x, z));
         }
     }
 }
@@ -117,7 +117,7 @@ int Platform::calculate_load() const {
     int load = 0;
     for (int y = 0; y < rocks.height; ++y) {
         for (int x = 0; x < rocks.width; ++x) {
-            if (rocks.at(x, y) == Rock::round) {
+            if (rocks.at_unchecked(x, y) == Rock::round) {
                 load += rocks.width - x;
             }
         }

diff --git a/2023/src/ds/grid.hpp b/2023/src/ds/grid.hpp
@@ -276,6 +276,12 @@ struct Grid {
     constexpr const_reference at(size_type x, size_type y) const {
         return m_data.at(get_index(x, y));
     }
+    constexpr reference at_unchecked(size_type x, size_type y) {
+        return m_data[get_index(x, y)];
+    }
+    constexpr const_reference at_unchecked(size_type x, size_type y) const {
+        return m_data[get_index(x, y)];
+    }
 
     // indexing by Pos
     constexpr reference at(const Pos &pos) { return at(pos.x, pos.y); }