publicvoidsolveSudoku(char[][] board) {
solver(board);
}
privatebooleansolver(char[][] board) {
for (inti=0; i<9; i++) {
for (intj=0; j<9; j++) {
if (board[i][j] =='.') {
charcount='1';
while (count<='9') {
if (isValid(i, j, board, count)) {
board[i][j] =count;
if (solver(board)) {
returntrue;
                        } else {
//下一个位置没有数字，就还原，然后当前位置尝试新的数board[i][j] ='.';
                        }
                    }
count++;
                }
returnfalse;
            }
        }
    }
returntrue;
}
privatebooleanisValid(introw, intcol, char[][] board, charc) {
for (inti=0; i<9; i++) {
if (board[row][i] ==c) {
returnfalse;
        }
    }
for (inti=0; i<9; i++) {
if (board[i][col] ==c) {
returnfalse;
        }
    }
intstart_row=row/3*3;
intstart_col=col/3*3;
for (inti=0; i<3; i++) {
for (intj=0; j<3; j++) {
if (board[start_row+i][start_col+j] ==c) {
returnfalse;
            }
        }
    }
returntrue;
}