1 files changed, 63 insertions, 4 deletions

diff --git a/src/day22.cpp b/src/day22.cpp
index 71320f5..1afb994 100644
--- a/src/day22.cpp
+++ b/src/day22.cpp
@@ -38,10 +38,8 @@ read_file(string_view filename)
 }
 
 void
-part1()
+part1(vector<piece> puzzle)
 {
-        auto puzzle = read_file("data/day22.txt");
-
         map<int, map<int, int>> grid;
 
         map<size_t, vector<size_t>> supported_by;
@@ -91,8 +89,69 @@ part1()
         cout << number << endl;
 }
 
+void
+part2(vector<piece> puzzle)
+{
+        map<int, map<int, int>> grid;
+
+        for ( auto& piece: puzzle ) {
+                int max_z = 0;
+                for ( auto x = piece.x1; x <= piece.x2; ++x ) {
+                        for ( auto y = piece.y1; y <= piece.y2; ++y ) {
+                                max_z = max(max_z, grid[x][y]);
+                        }
+                }
+
+                auto height = piece.z2 - piece.z1 + 1;
+
+                for ( auto x = piece.x1; x <= piece.x2; ++x ) {
+                        for ( auto y = piece.y1; y <= piece.y2; ++y ) {
+                                grid[x][y] = max_z + height;
+                        }
+                }
+
+                piece.z1 = max_z + 1;
+                piece.z2 = max_z + height;
+        }
+
+        int num = 0;
+        for ( size_t idx = 0; idx != puzzle.size(); ++idx ) {
+                map<int, map<int, int>> grid;
+
+                for ( size_t idx2 = 0; idx2 != puzzle.size(); ++idx2 ) {
+                        if ( idx == idx2 ) {
+                                continue;
+                        }
+
+                        const auto& piece = puzzle[idx2];
+
+                        int max_z = 0;
+                        for ( auto x = piece.x1; x <= piece.x2; ++x ) {
+                                for ( auto y = piece.y1; y <= piece.y2; ++y ) {
+                                        max_z = max(max_z, grid[x][y]);
+                                }
+                        }
+
+                        auto height = piece.z2 - piece.z1 + 1;
+
+                        for ( auto x = piece.x1; x <= piece.x2; ++x ) {
+                                for ( auto y = piece.y1; y <= piece.y2; ++y ) {
+                                        grid[x][y] = max_z + height;
+                                }
+                        }
+
+                        if ( piece.z1 != max_z + 1 ) {
+                                ++num;
+                        }
+                }
+        }
+        cout << num << endl;
+}
+
 int
 main()
 {
-        part1();
+        const auto puzzle = read_file("data/day22.txt");
+        part1(puzzle);
+        part2(puzzle);
 }