| 4 | 4 | // |
| 5 | 5 | |
| 6 | 6 | export class Board { |
| 7 | | constructor() { |
| 8 | | throw new Error('Remove this line and implement the function'); |
| 7 | constructor(board) { |
| 8 | // Edge Case: Handle empty or null board input |
| 9 | if (!board || board.length === 0) { |
| 10 | this.board = []; |
| 11 | this.height = 0; |
| 12 | this.width = 0; |
| 13 | return; |
| 14 | } |
| 15 | |
| 16 | // Parse the board into a 2D array |
| 17 | this.board = board.map(row => row.split('').filter(char => char !== ' ')); |
| 18 | this.height = this.board.length; |
| 19 | this.width = this.height > 0 ? this.board[0].length : 0; |
| 9 | 20 | } |
| 10 | 21 | |
| 11 | 22 | winner() { |
| 12 | | throw new Error('Remove this line and implement the function'); |
| 23 | // Edge Case: Handle empty board |
| 24 | if (this.height === 0 || this.width === 0) { |
| 25 | return ''; |
| 26 | } |
| 27 | |
| 28 | // Check if O (top to bottom) has won |
| 29 | if (this.checkWinner('O', true)) { |
| 30 | return 'O'; |
| 31 | } |
| 32 | |
| 33 | // Check if X (left to right) has won |
| 34 | if (this.checkWinner('X', false)) { |
| 35 | return 'X'; |
| 36 | } |
| 37 | |
| 38 | return ''; |
| 39 | } |
| 40 | |
| 41 | checkWinner(player, topToBottom) { |
| 42 | // Edge Case: Handle boards with invalid dimensions |
| 43 | if (this.height === 0 || this.width === 0) { |
| 44 | return false; |
| 45 | } |
| 46 | |
| 47 | const visited = Array(this.height).fill().map(() => Array(this.width).fill(false)); |
| 48 | const queue = []; |
| 49 | |
| 50 | if (topToBottom) { |
| 51 | // For O: check top row for starting positions |
| 52 | for (let col = 0; col < this.width; col++) { |
| 53 | if (this.board[0][col] === player) { |
| 54 | queue.push([0, col]); |
| 55 | visited[0][col] = true; |
| 56 | } |
| 57 | } |
| 58 | } else { |
| 59 | // For X: check left column for starting positions |
| 60 | for (let row = 0; row < this.height; row++) { |
| 61 | if (this.board[row][0] === player) { |
| 62 | queue.push([row, 0]); |
| 63 | visited[row][0] = true; |
| 64 | } |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | // Edge Case: No starting positions for the player |
| 69 | if (queue.length === 0) { |
| 70 | return false; |
| 71 | } |
| 72 | |
| 73 | // BFS to find a path |
| 74 | while (queue.length > 0) { |
| 75 | const [row, col] = queue.shift(); |
| 76 | |
| 77 | // Check if we've reached the target side |
| 78 | if (topToBottom) { |
| 79 | // For O: check if we reached bottom row |
| 80 | if (row === this.height - 1) { |
| 81 | return true; |
| 82 | } |
| 83 | } else { |
| 84 | // For X: check if we reached right column |
| 85 | if (col === this.width - 1) { |
| 86 | return true; |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | // Check all 6 hexagonal neighbors |
| 91 | const directions = [ |
| 92 | [-1, 0], [-1, 1], // top neighbors |
| 93 | [0, -1], [0, 1], // side neighbors |
| 94 | [1, -1], [1, 0] // bottom neighbors |
| 95 | ]; |
| 96 | |
| 97 | for (const [dr, dc] of directions) { |
| 98 | const newRow = row + dr; |
| 99 | const newCol = col + dc; |
| 100 | |
| 101 | // Edge Case: Check bounds |
| 102 | if (newRow >= 0 && newRow < this.height && |
| 103 | newCol >= 0 && newCol < this.width && |
| 104 | !visited[newRow][newCol] && |
| 105 | this.board[newRow][newCol] === player) { |
| 106 | |
| 107 | visited[newRow][newCol] = true; |
| 108 | queue.push([newRow, newCol]); |
| 109 | } |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | return false; |
| 13 | 114 | } |
| 14 | 115 | } |
| 116 | |
| 117 | // Handled Edge Cases: empty board, null board, boards with invalid dimensions, no starting positions for a player, out of bounds access |