/* Code for exercise 15.3. |  | "C++ Solutions--Companion to The C++ Programming Language, Third Edition" | by David Vandevoorde; Addison-Wesley 1998; ISBN 0-201-30965-3. | | Permission to use, copy, modify, distribute and sell this software | and its documentation for any purpose is hereby granted without fee. | The author makes no representations about the suitability of this | software for any purpose.  It is provided "as is" without express or | implied warranty. `----------------------------------------------------------------------*/#include <assert.h>#include "Board.H"Board::Board() {   for (int r = 0; r!=kNRows+2; ++r)      for (int c = 0; c!=kNRows+2; ++c)         b_[r][c] = kEmpty;   b_[kNRows/2+1][kNRows/2]      = b_[kNRows/2][kNRows/2+1] = kBlack;   b_[kNRows/2][kNRows/2]      = b_[kNRows/2+1][kNRows/2+1] = kWhite;   black_score_ = white_score_ = 2;}MoveResult Board::valid_move(Color color,                             int r, int c) const {   assert((r>=1) and (r<=kNRows)      and (c>=1) and (c<=kNCols));   if (b_[r][c]!=kEmpty)      return kUnsuccessful;   Color opponent = opponent_of(color);   for (int dr = -1; dr!=2; ++dr)      for (int dc = -1; dc!=2; ++dc)         if ((dr!=0) or (dc!=0)) {            int row = r, col = c;            do {               row += dr;               col += dc;            } while (b_[row][col]==opponent);            if ((b_[row][col]==color)            and ((row!=r+dr) or (col!=c+dc)))               return kSuccessful;         }   return kUnsuccessful;}void Board::move(Color color ,int r, int c) {   assert(valid_move(color, r, c));   Color opponent = opponent_of(color);   int count = 0;   for (int dr = -1; dr!=2; ++dr)      for (int dc = -1; dc!=2; ++dc)         if ((dr!=0) or (dc!=0)) {            int row = r, col = c;            do {               row += dr;               col += dc;            } while (b_[row][col]==opponent);            // If this direction captures something,            // change the color of the captured pieces:            if ((b_[row][col]==color)            and ((row!=r+dr) or (col!=c+dc)))               for (row = r+dr, col = c+dc;                    b_[row][col]==opponent;                    row += dr, col += dc) {                  b_[row][col] = color;                  ++count;               }         }   b_[r][c] = color;   if (color==kBlack) {      black_score_ += count+1;      white_score_ -= count;   } else {      white_score_ += count+1;      black_score_ -= count;   }}MoveResult Board::get_possible_move(Color color,                                    int &r, int &c) const {   for (r = 1; r!=kNRows+1; ++r)      for (c = 1; c!=kNCols+1; ++c)         if (valid_move(color, r, c))            return kSuccessful;   return kUnsuccessful;}