1import { sleep } from '@shared/utils';
2
3class Sudoku {
4  static readonly nums = [1, 2, 3, 4, 5, 6, 7, 8, 9];
5  static readonly square = 9;
6  static generateEmptyBoards() {
7    return new Array(Sudoku.square).fill(null).map(() => new Array(Sudoku.square).fill(null)) as (null | number)[][];
8  }
9  private row = 0;
10  private column = 0;
11  private original = Sudoku.generateEmptyBoards();
12  private direction: 'forward' | 'back' = 'forward';
13  private abortController?: AbortController;
14
15  public boards = Sudoku.generateEmptyBoards();
16
17  constructor(boards: (null | number)[][] = []) {
18    this.init(boards);
19  }
20
21  public init(boards: (null | number)[][]) {
22    for (let i = 0; i < this.original.length; i += 1) {
23      for (let j = 0; j < this.original[i].length; j += 1) {
24        this.original[i][j] = boards?.[i]?.[j] ?? null;
25      }
26    }
27    this.reset();
28  }
29  public reset() {
30    this.row = 0;
31    this.column = 0;
32    this.boards = this.original.map(row => [...row]);
33  }
34  public fill() {
35    if (this.original[this.row][this.column] === null) {
36      const rows = this.boards[this.row];
37      const columns = this.boards.map(row => row[this.column]);
38      const startColumn = this.column - this.column % 3;
39      const startRow = this.row - this.row % 3;
40      const squares = this.boards.reduce((pre, current, index) => {
41        if (index >= startRow && index < startRow + 3) {
42          pre.push(...current.slice(startColumn, startColumn + 3));
43        }
44        return pre;
45      }, [] as (number | null)[]);
46      const availableNums = Sudoku.nums.filter(num => !rows.includes(num) && !columns.includes(num) && !squares.includes(num));
47      const available = availableNums.find(num => {
48        const current = this.boards[this.row][this.column];
49        return current === null || num > current;
50      });
51      if (available) {
52        this.boards[this.row][this.column] = available;
53        this.direction = 'forward';
54      } else {
55        this.boards[this.row][this.column] = null;
56        this.direction = 'back';
57      }
58    }
59  }
60  private round() {
61    if (this.column > Sudoku.square - 1) {
62      this.row += 1;
63      this.column = 0;
64      return true;
65    }
66    if (this.column < 0) {
67      this.row -= 1;
68      this.column = Sudoku.square - 1;
69      return true;
70    }
71    this.fill();
72    this.column = this.direction === 'forward' ? this.column + 1 : this.column - 1;
73    return false;
74  }
75  public destroy() {
76    this.abortController?.abort();
77  }
78  public async async(cb?: (boards: (number | null)[][]) => void, millisecond = 0) {
79    this.abortController = new AbortController();
80    this.reset();
81    while (this.row < Sudoku.square && this.row >= 0) {
82      if (this.round()) continue;
83      await sleep(millisecond, this.abortController.signal);
84      cb?.(this.boards);
85    }
86    if (this.row < 0) {
87      throw new Error('无解');
88    }
89    return this.boards;
90  }
91  public sync() {
92    this.reset();
93    while (this.row < Sudoku.square && this.row >= 0) {
94      this.round();
95    }
96    if (this.row < 0) {
97      throw new Error('无解');
98    }
99    return this.boards;
100  }
101}
102
103export { Sudoku };