leetcode medium

minesweeper.ts

type Coordinate = [number, number];

function updateBoard(board: string[][], click: number[]): string[][] {
 const boardCopy = [...board];
    const coordinates: Coordinate = [click[0], click[1]];
    const result = traverse(boardCopy, coordinates);
    
    return result;
};

const traverse = (
    board: string[][],
    coordinates: Coordinate,
  ) => {
    if (!validateCoord(coordinates, board.length, board[0].length)) return board;
    const [x, y] = coordinates;
    if (board[x][y] === "B") { return board; }

    console.log(`traversing ${x}, ${y}...`);

    if (board[x][y] === "M") {
      board[x][y] = "X";
      return board;
    }
    const count = countAdjacentMines(board, [x, y]);

    if (count) {
      board[x][y] = String(count);
      return board;
    }
      
    board[x][y] = 'B';

    traverse(board, [x - 1, y]);
    traverse(board, [x - 1, y + 1]);
    traverse(board, [x, y + 1]);
    traverse(board, [x + 1, y + 1]);
    traverse(board, [x + 1, y]);
    traverse(board, [x + 1, y - 1]);
    traverse(board, [x, y - 1]);
    traverse(board, [x - 1, y - 1]);

    return board;
  };


const countAdjacentMines = (board: string[][], coord: [number, number]) => {
  const [x, y] = coord;
  let count = 0;

  if (board[x - 1]?.[y - 1] === "M") count += 1;
  if (board[x - 1]?.[y] === "M") count += 1;
  if (board[x - 1]?.[y + 1] === "M") count += 1;
  if (board[x]?.[y - 1] === "M") count += 1;
  if (board[x]?.[y] === "M") count += 1;
  if (board[x]?.[y + 1] === "M") count += 1;
  if (board[x + 1]?.[y - 1] === "M") count += 1;
  if (board[x + 1]?.[y] === "M") count += 1;
  if (board[x + 1]?.[y + 1] === "M") count += 1;

  return count;
};

const validateCoord = (coords: Coordinate, maxX: number, maxY: number) => {
  const [x, y] = coords;
  if (x >= 0 && x < maxX && y >= 0 && y < maxY) return true;

  return false;
};