- const int MateTable[SQUARE_NB] = {
- 100, 90, 80, 70, 70, 80, 90, 100,
- 90, 70, 60, 50, 50, 60, 70, 90,
- 80, 60, 40, 30, 30, 40, 60, 80,
- 70, 50, 30, 20, 20, 30, 50, 70,
- 70, 50, 30, 20, 20, 30, 50, 70,
- 80, 60, 40, 30, 30, 40, 60, 80,
- 90, 70, 60, 50, 50, 60, 70, 90,
- 100, 90, 80, 70, 70, 80, 90, 100,
- };
-
- // Table used to drive the defending king towards a corner square of the
- // right color in KBN vs K endgames.
- const int KBNKMateTable[SQUARE_NB] = {
- 200, 190, 180, 170, 160, 150, 140, 130,
- 190, 180, 170, 160, 150, 140, 130, 140,
- 180, 170, 155, 140, 140, 125, 140, 150,
- 170, 160, 140, 120, 110, 140, 150, 160,
- 160, 150, 140, 110, 120, 140, 160, 170,
- 150, 140, 125, 140, 140, 155, 170, 180,
- 140, 130, 140, 150, 160, 170, 180, 190,
- 130, 140, 150, 160, 170, 180, 190, 200
- };
-
- // The attacking side is given a descending bonus based on distance between
- // the two kings in basic endgames.
- const int DistanceBonus[8] = { 0, 0, 100, 80, 60, 40, 20, 10 };
-
- // Get the material key of a Position out of the given endgame key code
- // like "KBPKN". The trick here is to first forge an ad-hoc fen string
- // and then let a Position object to do the work for us. Note that the
- // fen string could correspond to an illegal position.
- Key key(const string& code, Color c) {
-
- assert(code.length() > 0 && code.length() < 8);
- assert(code[0] == 'K');
-
- string sides[] = { code.substr(code.find('K', 1)), // Weaker
- code.substr(0, code.find('K', 1)) }; // Stronger
-
- std::transform(sides[c].begin(), sides[c].end(), sides[c].begin(), tolower);
-
- string fen = sides[0] + char('0' + int(8 - code.length()))
- + sides[1] + "/8/8/8/8/8/8/8 w - - 0 10";
-
- return Position(fen, false, NULL).material_key();