init

1 files changed, 134 insertions, 0 deletions

diff --git a/day04/day04.cpp b/day04/day04.cpp
new file mode 100644
index 0000000..7736eff
--- /dev/null
+++ b/day04/day04.cpp
@@ -0,0 +1,134 @@
+#include <iostream>
+#include <fstream>
+#include <vector>
+
+void split (std::vector<std::string> &vec, std::string str, std::string del) {
+	auto token = str.find(del);
+	if (token != std::string::npos) {
+		vec.push_back(str.substr(0, token));
+		split(vec, str.substr(token+del.size()), del);
+	} else { vec.push_back(str); }
+}
+
+class Board {
+	public:
+	Board(std::string repr) { 
+		std::vector<std::string> lines;
+		split(lines, repr, "\n");
+		for (auto line : lines) {
+			std::vector<std::string> strcells;
+			split(strcells, line, " ");
+			size = 0;
+			for (auto strcell : strcells) {
+				if (strcell.size() == 0) continue;
+				cells.push_back(std::stoi(strcell));
+				state.push_back(0);
+				size++;
+			}
+		}
+
+	}
+
+	int size;
+	std::vector<int> cells;
+	std::vector<int> state;
+
+	void mark (int ex) {
+		for (int y=0; y<size; y++) {
+			for (int x=0; x<size; x++) {
+				int i = x + y*size;
+				if (cells[i] == ex) {
+					state[i] = 1;
+				}
+			}
+		}
+	}
+
+	bool win () {
+		for (int y=0; y<size; y++) {
+			int sum_row = 0;
+			for (int x=0; x<size; x++) {
+				int i = x + y*size;
+				sum_row += state[i];
+			}
+			if (sum_row == size) return true;
+		}
+		for (int x=0; x<size; x++) {
+			int sum_col = 0;
+			for (int y=0; y<size; y++) {
+				int i = x + y*size;
+				sum_col += state[i];
+			}
+			if (sum_col == size) return true;
+		}
+		return false;
+	}
+
+	int score () {
+		int sum = 0;
+		for (int y=0; y<size; y++) {
+			for (int x=0; x<size; x++) {
+				int i = x + y*size;
+				if (state[i] == 0) {
+					sum += cells[i];
+				}
+			}
+		}
+		return sum;
+	}
+};
+
+int main (int argc, char *argv[]) {
+	if (argc != 2) return 1;
+	std::string raw;
+	std::getline(std::ifstream(argv[1]), raw, '\0');
+
+	std::vector<int> extract;
+	auto token = raw.find("\n");
+	if (token != std::string::npos) {
+		std::string ex = raw.substr(0, token);
+		std::vector<std::string> vec;
+	   	split(vec, ex, ",");
+		for (auto v : vec) { extract.push_back(std::stoi(v)); }
+
+		raw = raw.substr(token+2);
+		if (raw[raw.size()-1] == '\n') raw = raw.substr(0, raw.size()-1); 
+	} else return 1;
+
+	std::vector<Board> boards;
+
+	std::vector<std::string> str_boards;
+	split(str_boards, raw, "\n\n");
+	for (auto s : str_boards) {
+		boards.emplace_back(s);
+	}
+
+	bool flag = false;
+	std::vector<Board> filtered = boards;
+	for (int ex : extract) {
+		std::cout << ex << " " << filtered.size() << std::endl;
+		std::vector<Board> next;
+		int size = filtered.size(), seen = 0;;
+		for (auto& board : filtered) {
+			board.mark(ex);
+			if (board.win() && filtered.size() != 1) {
+				if (!flag) {
+					std::cout << "first winner product: " << ex * board.score() << ", "
+						<< "ex: " << ex << ", score: " << board.score() << std::endl;
+					flag = true;
+				}
+			} else {
+				next.push_back(board);
+			}
+		}
+		if (next.size() == 1 && next[0].win()) {
+			int score = next[0].score();
+			std::cout << "last winner product: " << ex * score << ", "
+				<< "ex: " << ex << ", score: " << score << std::endl;
+			break;
+		}
+		filtered = next;
+	}
+
+	return 0;
+}