Finished aoc day 8

advent_of_code/2022/8/main.cpp

@@ -2,6 +2,51 @@
 
 using namespace std;
 
+int WIDTH, HEIGHT;
+
+int scenic_score(int i, int j, const vector<vector<int>>& tree_height_map){
+    int left = 0, right = 0, up = 0, down = 0;
+    int tree_height = tree_height_map[i][j];
+
+    // Look to the right
+    for(int x = j + 1; x < WIDTH; ++x){
+        if(tree_height_map[i][x] >= tree_height){
+            right++;
+            break;
+        }
+        right++;
+    }
+
+    // Look to the left
+    for(int x = j - 1; x >= 0; --x){
+        if(tree_height_map[i][x] >= tree_height){
+            left++;
+            break;
+        }
+        left++;
+    }
+
+    // Look down
+    for(int y = i + 1; y < HEIGHT; ++y){
+        if(tree_height_map[y][j] >= tree_height){
+            down++;
+            break;
+        }
+        down++;
+    }
+
+    // Look up
+    for(int y = i - 1; y >= 0; --y){
+        if(tree_height_map[y][j] >= tree_height){
+            up++;
+            break;
+        }
+        up++;
+    }
+
+    return left * right * up * down;
+}
+
 int main(){
     ifstream input_file("input.txt");
     string line;
@@ -16,22 +61,22 @@ int main(){
         tree_height_map.push_back(acc);
     }
 
-    size_t WIDTH = tree_height_map.at(0).size();
-    size_t HEIGHT = tree_height_map.size();
+    WIDTH = tree_height_map.at(0).size();
+    HEIGHT = tree_height_map.size();
 
     vector<vector<bool>> spotted_trees;
     vector<bool> dummy(WIDTH, false);
-    for(size_t i = 0; i < HEIGHT; ++i){
+    for(int i = 0; i < HEIGHT; ++i){
         spotted_trees.push_back(dummy);
     }
 
     int result = 0;
     // Now check from all directions
     // Left to right first
-    for(size_t i = 0; i < HEIGHT; ++i){
+    for(int i = 0; i < HEIGHT; ++i){
         int highest_tree = -1;
 
-        for(size_t j = 0; j < WIDTH; ++j){
+        for(int j = 0; j < WIDTH; ++j){
             if(tree_height_map[i][j] > highest_tree){
                 highest_tree = tree_height_map[i][j];
 
@@ -44,10 +89,10 @@ int main(){
     }
 
     // From right to left
-    for(size_t i = 0; i < HEIGHT; ++i){
+    for(int i = 0; i < HEIGHT; ++i){
         int highest_tree = -1;
 
-        for(size_t j = WIDTH; j > 0; --j){
+        for(int j = WIDTH; j > 0; --j){
             if(tree_height_map[i][j-1] > highest_tree){
                 highest_tree = tree_height_map[i][j-1];
 
@@ -60,10 +105,10 @@ int main(){
     }
 
     // From top to bottom
-    for(size_t j = 0; j < WIDTH; ++j){
+    for(int j = 0; j < WIDTH; ++j){
         int highest_tree = -1;
 
-        for(size_t i = 0; i < HEIGHT; ++i){
+        for(int i = 0; i < HEIGHT; ++i){
             if(tree_height_map[i][j] > highest_tree){
                 highest_tree = tree_height_map[i][j];
 
@@ -76,10 +121,10 @@ int main(){
     }
 
     // From bottom to top
-    for(size_t j = 0; j < WIDTH; ++j){
+    for(int j = 0; j < WIDTH; ++j){
         int highest_tree = -1;
         
-        for(size_t i = HEIGHT; i > 0; --i){
+        for(int i = HEIGHT; i > 0; --i){
             if(tree_height_map[i-1][j] > highest_tree){
                 highest_tree = tree_height_map[i-1][j];
 
@@ -93,5 +138,18 @@ int main(){
 
     cout << "Number of spotted trees: " << result << endl;
 
+    // For part 2, let's try checking all hidden trees on their viewing distances
+    // and see if we're not too slow with such a brute force
+
+    int max_scenic_score = 0;
+    for(int i = 0; i < HEIGHT; ++i){
+        for(int j = 0; j < WIDTH; ++j){
+            if(spotted_trees[i][j]){
+                max_scenic_score = max(max_scenic_score, scenic_score(i, j, tree_height_map));
+            }
+        }
+    }
+    cout << "Maximal scenic score: " << max_scenic_score << endl;
+
     return 0;
 }