int main() {
Solution s;
{
auto board =
buildBoard(vector<string>{
"53..7....",
"6..195...",
".98....6.",
"8...6...3",
"4..8.3..1",
"7...2...6",
".6....28.",
"...419..5",
"....8..79",
});
s.solveSudoku(board);
printBoard(board);
}
{
auto board =
buildBoard(vector<string>{
"..9748...",
"7........",
".2.1.9...",
"..7...24.",
".64.1.59.",
".98...3..",
"...8.3.2.",
"........6",
"...2759..",
});
s.solveSudoku(board);
printBoard(board);
}
}
}
constexpr Board buildBoardScan(int N, int Col, int Row, const Board &B) {
return Row == N ? Board(0, true) :
B.ok(Row, Col) ?
tryBoard(buildBoardRecurse(N, Col + 1, B.addQueen(Row, Col)),
N, Col, Row+1, B) :
buildBoardScan(N, Col, Row + 1, B);
}
constexpr Board buildBoardRecurse(int N, int Col, const Board &B) {
return Col == N ? B : buildBoardScan(N, Col, 0, B);
}
constexpr Board buildBoard(int N) {
return buildBoardRecurse(N, 0, Board());
}
constexpr Board q8 = buildBoard(8);
constexpr bool Board::check(const char *p, int Row, int Col) {
return
*p == '\n' ? check(p+1, Row+1, 0) :
*p == 'o' ? at(Row, Col) && check(p+1, Row, Col+1) :
*p == '-' ? !at(Row, Col) && check(p+1, Row, Col+1) :
*p == 0 ? true :
false;
}
constexpr bool check = q8.check(
"o-------\n"
"------o-\n"
"----o---\n"
"-------o\n"
"-o------\n"
