Make Grid iterable

2022/08.cpp

@@ -22,7 +22,7 @@ Dir directions[4] {Up, Down, Left, Right};
 auto Part1(Grid const& grid) -> std::int64_t
 {
   std::int64_t result {0};
-  grid.each([&](Coord const c, char const v) {
+  for (auto [c, v] : grid) {
     result += std::any_of(
       std::begin(directions), std::end(directions),
       [&](Dir const dir) {
@@ -31,14 +31,14 @@ auto Part1(Grid const& grid) -> std::int64_t
         }
         return true;
       });
-  });
+  }
   return result;
 }
 
 auto Part2(Grid const& grid) -> std::int64_t
 {
   std::int64_t result {0};
-  grid.each([&](Coord const c, char const v) {
+  for (auto [c, v] : grid) {
     auto score = std::transform_reduce(
       std::begin(directions), std::end(directions),
       std::int64_t{1}, std::multiplies(), // product
@@ -51,7 +51,7 @@ auto Part2(Grid const& grid) -> std::int64_t
         return count;
       });
     if (result < score) result = score;
-  });
+  }
   return result;
 }
 

2022/12.cpp

@@ -27,13 +27,13 @@ auto Parse(std::istream & in) -> std::tuple<Coord, std::vector<Coord>, Coord, Gr
   auto& end = std::get<2>(result);
   auto& grid = std::get<3>(result);
 
-  grid.each([&](Coord c, char v) {
+  for (auto [c, v] : grid) {
     switch (v) {
       case 'S': grid[c] = 'a'; start1 = c; break;
       case 'E': grid[c] = 'z'; end   = c; break;
       case 'a': starts2.push_back(c);     break;
     }
-  });
+  }
 
   return result;
 }