diff options
Diffstat (limited to 'board.h')
-rw-r--r-- | board.h | 78 |
1 files changed, 78 insertions, 0 deletions
@@ -0,0 +1,78 @@ +#pragma once + +#include <iostream> +#include <optional> +#include <string_view> +#include <cstdint> + +using namespace std; + +const int N = 9; +const int BOARDMID = N * (N/2) + N/2; + +const uint8_t EMPTY = 0, WHITE = 1, KING = 2, BLACK = 4; + + +struct Move { + int from, to; + + Move() = default; + Move(int from, int to); + + static optional<Move> parse(string_view str); +}; + +struct Board { + uint8_t cells[N * N]; + + static Board makeInitial(); + + void apply(Move mv); + int applyCW(Move mv); + int checkWin() const; // 1=win white, -1=win black, 0=none yet + + bool isValid(Move mv, int player) const; + + // Calls the callback for each valid move of the specified player. + // F should have a signature compatible with bool F(Move mv). + // If the callback returns true, iteration is stopped. + // Callback should not modify this Board instance. + template <typename F> + void forEachMove(int player, F callback) const; + +private: + Board(); + + bool isValid(Move mv) const; + bool stoneFlankedH(int pos, uint8_t by) const; + bool stoneFlankedV(int pos, uint8_t by) const; + bool kingEncircled(int pos) const; +}; + +ostream& operator<<(ostream &os, const Move &mv); +ostream& operator<<(ostream &os, const Board &bd); + + +template <typename F> +void Board::forEachMove(int player, F callback) const { + static const int deltas[4][2] = {{-1, 0}, {0, -1}, {1, 0}, {0, 1}}; + + for (int y = 0; y < N; y++) + for (int x = 0; x < N; x++) { + uint8_t v = cells[N * y + x]; + if (player == 1 ? v != WHITE && v != KING : v != BLACK) continue; + + for (int i = 0; i < 4; i++) { + int x2 = x + deltas[i][0], y2 = y + deltas[i][1]; + while (x2 >= 0 && x2 < N && y2 >= 0 && y2 < N) { + if (cells[N * y2 + x2] != EMPTY) break; + if (N * y2 + x2 != BOARDMID) { + callback(Move(N * y + x, N * y2 + x2)); + } + + x2 += deltas[i][0]; + y2 += deltas[i][1]; + } + } + } +} |