#include #include #include #include #include #include #include #include #include "common.hpp" using Position = std::tuple; using Board = std::map; std::vector readInput(const std::string &filename) { std::vector input; std::string line; std::ifstream file(filename); while (std::getline(file, line)) { input.push_back(line); } return input; } Board parseBoard(const std::vector &input) { Board board; int rowCursor = 0; for (auto rowIterator = input.cbegin(); rowIterator != input.cend(); (rowCursor++, ++rowIterator)) { auto &line = *rowIterator; int colCursor = 0; for (auto colIterator = line.cbegin(); colIterator != line.cend(); (colCursor++, ++colIterator)) { CellState state = *colIterator == ALIVE_CHAR ? ALIVE : DEAD; Position position(rowCursor, colCursor, 0, 0); board.emplace(std::move(position), std::move(state)); } } return board; } int getNumAdjacentLiveNeighbors(const Board &board, int row, int col, int depth, int w) { int count = 0; for (int dRow = -1; dRow <= 1; dRow++) { for (int dCol = -1; dCol <= 1; dCol++) { for (int dDepth = -1; dDepth <= 1; dDepth++) { for (int dW = -1; dW <= 1; dW++) { if (dRow == 0 && dCol == 0 && dDepth == 0 && dW == 0) { continue; } Position position(row + dRow, col + dCol, depth + dDepth, w + dW); if (board.find(position) == board.end()) { continue; } count += (board.at(position) == ALIVE); } } } } return count; } /** * Get the range alive positions of each component * @param board The board to check * @return std::pair The min and max of each component on the board */ std::pair getRangeOnEachAxis(const Board &board) { std::pair rowRange = getMinMaxAlivePositionsForComponent(board); std::pair colRange = getMinMaxAlivePositionsForComponent(board); std::pair depthRange = getMinMaxAlivePositionsForComponent(board); std::pair wRange = getMinMaxAlivePositionsForComponent(board); return std::pair( Position(rowRange.first, colRange.first, depthRange.first, wRange.first), Position(rowRange.second, colRange.second, depthRange.second, wRange.second)); } int run(const std::vector &input) { Board board = parseBoard(input); Board nextBoard = board; for (int i = 0; i < CYCLE_COUNT; i++) { auto ranges = getRangeOnEachAxis(board); for (int row = std::get<0>(ranges.first) - 1; row <= std::get<0>(ranges.second) + 1; row++) { for (int col = std::get<1>(ranges.first) - 1; col <= std::get<1>(ranges.second) + 1; col++) { for (int depth = std::get<2>(ranges.first) - 1; depth <= std::get<2>(ranges.second) + 1; depth++) { for (int w = std::get<3>(ranges.first) - 1; w <= std::get<3>(ranges.second) + 1; w++) { int aliveNeighbors = getNumAdjacentLiveNeighbors(board, row, col, depth, w); Position position(row, col, depth, w); CellState state = getOrDefault(board, DEAD, position); if (aliveNeighbors != 2 && aliveNeighbors != 3) { state = DEAD; } else if (state == DEAD && aliveNeighbors == 3) { state = ALIVE; } nextBoard[position] = state; } } } } std::swap(nextBoard, board); } return std::count_if( board.cbegin(), board.cend(), [](const std::pair &item) { return item.second == ALIVE; }); } int main(int argc, char *argv[]) { if (argc != 2) { std::cerr << argv[0] << " " << std::endl; return 1; } auto input = readInput(argv[1]); std::cout << run(input) << std::endl; }