尝试使用typescript和回溯解决数独的错误

class SudokuSolver {
  solveSudoku(board: number[][]): boolean {
    const n = board.length;
    const digits = ['1', '2', '3', '4', '5', '6', '7', '8', '9'];

    function isValid(row: number, col: number, digit: string): boolean {
      // 检查行是否有重复数字
      for (let i = 0; i < n; i++) {
        if (board[row][i] === digit) {
          return false;
        }
      }

      // 检查列是否有重复数字
      for (let i = 0; i < n; i++) {
        if (board[i][col] === digit) {
          return false;
        }
      }

      // 检查3x3子网格是否有重复数字
      const startRow = Math.floor(row / 3) * 3;
      const startCol = Math.floor(col / 3) * 3;
      for (let i = 0; i < 3; i++) {
        for (let j = 0; j < 3; j++) {
          if (board[startRow + i][startCol + j] === digit) {
            return false;
          }
        }
      }

      return true;
    }

    function solve(): boolean {
      for (let row = 0; row < n; row++) {
        for (let col = 0; col < n; col++) {
          if (board[row][col] === 0) {
            for (const digit of digits) {
              if (isValid(row, col, digit)) {
                board[row][col] = digit;
                if (solve()) {
                  return true;
                }
                board[row][col] = 0; // 回溯
              }
            }
            return false;
          }
        }
      }
      return true;
    }

    return solve();
  }
}

// 示例用法
const solver = new SudokuSolver();
const board = [
  [5, 3, 0, 0, 7, 0, 0, 0, 0],
  [6, 0, 0, 1, 9, 5, 0, 0, 0],
  [0, 9, 8, 0, 0, 0, 0, 6, 0],
  [8, 0, 0, 0, 6, 0, 0, 0, 3],
  [4, 0, 0, 8, 0, 3, 0, 0, 1],
  [7, 0, 0, 0, 2, 0, 0, 0, 6],
  [0, 6, 0, 0, 0, 0, 2, 8, 0],
  [0, 0, 0, 4, 1, 9, 0, 0, 5],
  [0, 0, 0, 0, 8, 0, 0, 7, 9],
];
solver.solveSudoku(board);
console.log(board);