| 8 | 8 | * @param {string[]} board |
| 9 | 9 | */ |
| 10 | 10 | constructor(board) { |
| 11 | | throw new Error('Remove this line and implement the function'); |
| 11 | // Edge Case: Handle empty board |
| 12 | if (!board || board.length === 0) { |
| 13 | this.board = []; |
| 14 | this.height = 0; |
| 15 | this.width = 0; |
| 16 | return; |
| 17 | } |
| 18 | |
| 19 | // Normalize the board by trimming leading spaces and converting to array of arrays |
| 20 | // For hexagonal boards, we need to handle the space-separated format properly |
| 21 | this.board = board.map(row => { |
| 22 | // Remove leading spaces and split by spaces to get individual cells |
| 23 | const trimmed = row.replace(/^\s+/, ''); |
| 24 | return trimmed.split(/\s+/); // Split by one or more spaces |
| 25 | }); |
| 26 | this.height = this.board.length; |
| 27 | this.width = this.height > 0 ? this.board[0].length : 0; |
| 12 | 28 | } |
| 13 | 29 | |
| 14 | 30 | /** |
| 15 | 31 | * @return {'X' | 'O' | ''} |
| 16 | 32 | */ |
| 17 | 33 | winner() { |
| 18 | | throw new Error('Remove this line and implement the function'); |
| 34 | // Edge Case: Handle empty board |
| 35 | if (this.height === 0 || this.width === 0) { |
| 36 | return ''; |
| 37 | } |
| 38 | |
| 39 | // Check if O (top to bottom) has won |
| 40 | if (this.checkWinner('O')) { |
| 41 | return 'O'; |
| 42 | } |
| 43 | |
| 44 | // Check if X (left to right) has won |
| 45 | if (this.checkWinner('X')) { |
| 46 | return 'X'; |
| 47 | } |
| 48 | |
| 49 | return ''; |
| 50 | } |
| 51 | |
| 52 | /** |
| 53 | * @param {'X' | 'O'} player |
| 54 | * @return {boolean} |
| 55 | */ |
| 56 | checkWinner(player) { |
| 57 | const visited = Array(this.height).fill().map(() => Array(this.width).fill(false)); |
| 58 | |
| 59 | if (player === 'O') { |
| 60 | // For O, check if there's a path from top to bottom |
| 61 | for (let col = 0; col < this.width; col++) { |
| 62 | if (this.board[0][col] === player && !visited[0][col]) { |
| 63 | if (this.dfs(0, col, player, visited, 'vertical')) { |
| 64 | return true; |
| 65 | } |
| 66 | } |
| 67 | } |
| 68 | } else if (player === 'X') { |
| 69 | // For X, check if there's a path from left to right |
| 70 | for (let row = 0; row < this.height; row++) { |
| 71 | if (this.board[row][0] === player && !visited[row][0]) { |
| 72 | if (this.dfs(row, 0, player, visited, 'horizontal')) { |
| 73 | return true; |
| 74 | } |
| 75 | } |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | return false; |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * @param {number} row |
| 84 | * @param {number} col |
| 85 | * @param {'X' | 'O'} player |
| 86 | * @param {boolean[][]} visited |
| 87 | * @param {'vertical' | 'horizontal'} direction |
| 88 | * @return {boolean} |
| 89 | */ |
| 90 | dfs(row, col, player, visited, direction) { |
| 91 | // Check bounds |
| 92 | if (row < 0 || row >= this.height || col < 0 || col >= this.width) { |
| 93 | return false; |
| 94 | } |
| 95 | |
| 96 | // Check if already visited or not the player's stone |
| 97 | if (visited[row][col] || this.board[row][col] !== player) { |
| 98 | return false; |
| 99 | } |
| 100 | |
| 101 | // Check win condition |
| 102 | if (player === 'O' && direction === 'vertical' && row === this.height - 1) { |
| 103 | return true; // Reached bottom row |
| 104 | } |
| 105 | |
| 106 | if (player === 'X' && direction === 'horizontal' && col === this.width - 1) { |
| 107 | return true; // Reached rightmost column |
| 108 | } |
| 109 | |
| 110 | // Mark as visited |
| 111 | visited[row][col] = true; |
| 112 | |
| 113 | // Hexagonal neighbors - correct pattern for hexagonal grid |
| 114 | const neighbors = []; |
| 115 | |
| 116 | // Standard hexagonal neighbors (6 directions) |
| 117 | neighbors.push( |
| 118 | [row - 1, col], // Top |
| 119 | [row + 1, col], // Bottom |
| 120 | [row, col - 1], // Left |
| 121 | [row, col + 1], // Right |
| 122 | [row - 1, col - 1], // Top-left |
| 123 | [row + 1, col + 1] // Bottom-right |
| 124 | ); |
| 125 | |
| 126 | // Check all neighbors |
| 127 | for (const [nRow, nCol] of neighbors) { |
| 128 | if (this.dfs(nRow, nCol, player, visited, direction)) { |
| 129 | return true; |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | return false; |
| 19 | 134 | } |
| 20 | 135 | } |
| 136 | |
| 137 | // Handled Edge Cases: empty board, invalid board dimensions, disconnected components, games with no winner yet |