Day08

src/days/08/Day08.cpp

@@ -1,9 +1,97 @@
 #include "Day08.h"
 
 Result Day08::Task1() {
-	return Day::Task1();
+	size_t w, h;
+	vector<vector<int>> grid = parseGrid(w, h);
+
+	size_t count = w * 2 + (h - 2) * 2;
+
+	auto checkVisible = [grid, w, h](size_t rIdx, size_t cIdx) -> bool {
+		auto checkDir = [grid, w, h, rIdx, cIdx](int rV, int cV){
+			set<int> values;
+			if (rV != 0)
+				for (int rLook = int(rIdx) + rV; rLook >= 0 && rLook < h; rLook += rV)
+					values.insert(grid[rLook][cIdx]);
+			if (cV != 0)
+				for (int cLook = int(cIdx) + cV; cLook >= 0 && cLook < w; cLook += cV)
+					values.insert(grid[rIdx][cLook]);
+			return *std::max_element(values.begin(), values.end()) < grid[rIdx][cIdx];
+		};
+
+		return checkDir(1, 0) ||
+			checkDir(-1, 0) ||
+			checkDir(0, 1) ||
+			checkDir(0, -1);
+	};
+
+	for (size_t rIdx = 1; rIdx < h - 1; rIdx++)
+		for (size_t cIdx = 1; cIdx < w - 1; cIdx++)
+			if (checkVisible(rIdx, cIdx)) count++;
+
+
+	return to_string(count);
 }
 
 Result Day08::Task2() {
-	return Day::Task2();
-}
+	size_t w, h;
+	vector<vector<int>> grid = parseGrid(w, h);
+
+	auto look = [grid, w, h](size_t rIdx, size_t cIdx, int rV, int cV){
+		int dist = 0;
+		if (cV != 0){
+			for (int cLook = int(cIdx) + cV; 0 <= cLook && cLook < w; cLook += cV){
+				dist++;
+				if (grid[rIdx][cLook] >= grid[rIdx][cIdx])
+					break;
+			}
+		}
+		if (rV != 0){
+			for (int rLook = int(rIdx) + rV; 0 <= rLook && rLook < h; rLook += rV){
+				dist++;
+				if (grid[rLook][cIdx] >= grid[rIdx][cIdx])
+					break;
+			}
+		}
+
+		return dist;
+	};
+
+	auto lookVertical = [look](size_t rIdx, size_t cIdx, int dir) -> int {
+		return look(rIdx, cIdx, dir, 0);
+	};
+
+	auto lookHorizontal = [look](size_t rIdx, size_t cIdx, int dir) -> int {
+		return look(rIdx, cIdx, 0, dir);
+	};
+
+	set<int> scores;
+	for (size_t rIdx = 1; rIdx < h - 1; rIdx++){
+		for (size_t cIdx = 1; cIdx < w - 1; cIdx++){
+			int up = lookVertical(rIdx, cIdx, -1);
+			int down = lookVertical(rIdx, cIdx, 1);
+			int left = lookHorizontal(rIdx, cIdx, -1);
+			int right = lookHorizontal(rIdx, cIdx, 1);
+			scores.insert(up * down * left * right);
+		}
+	}
+
+	int max = *std::max_element(scores.begin(), scores.end());
+
+	return to_string(max);
+}
+
+vector<vector<int>> Day08::parseGrid(size_t &w, size_t &h) {
+	vector<vector<int>> grid;
+
+	for (const string &line : input){
+		vector<int> row;
+		for (const char &item: line)
+			row.emplace_back(item - '0');
+		grid.push_back(row);
+	}
+
+	w = input[0].size();
+	h = input.size();
+
+	return grid;
+}

src/days/08/Day08.h

@@ -7,4 +7,6 @@ protected:
 	Result Task1() override;
 
 	Result Task2() override;
+
+	vector<vector<int>> parseGrid(size_t&, size_t&);
 };