本文實例講述了JS實現(xiàn)判斷有效的數(shù)獨算法。分享給大家供大家參考，具體如下：

判斷一個 9x9 的數(shù)獨是否有效。只需要根據(jù)以下規(guī)則，驗證已經填入的數(shù)字是否有效即可。

1.數(shù)字 1-9 在每一行只能出現(xiàn)一次。
2.數(shù)字 1-9 在每一列只能出現(xiàn)一次。
3.數(shù)字 1-9 在每一個以粗實線分隔的 3x3 宮內只能出現(xiàn)一次。

數(shù)獨部分空格內已填入了數(shù)字，空白格用 ‘.' 表示。

示例 1:

輸入:

[
["5","3",".",".","7",".",".",".","."],
["6",".",".","1","9","5",".",".","."],
[".","9","8",".",".",".",".","6","."],
["8",".",".",".","6",".",".",".","3"],
["4",".",".","8",".","3",".",".","1"],
["7",".",".",".","2",".",".",".","6"],
[".","6",".",".",".",".","2","8","."],
[".",".",".","4","1","9",".",".","5"],
[".",".",".",".","8",".",".","7","9"]
]

輸出: true

示例 2:

輸入:

[
["8","3",".",".","7",".",".",".","."],
["6",".",".","1","9","5",".",".","."],
[".","9","8",".",".",".",".","6","."],
["8",".",".",".","6",".",".",".","3"],
["4",".",".","8",".","3",".",".","1"],
["7",".",".",".","2",".",".",".","6"],
[".","6",".",".",".",".","2","8","."],
[".",".",".","4","1","9",".",".","5"],
[".",".",".",".","8",".",".","7","9"]
]

輸出: false

解釋: 除了第一行的第一個數(shù)字從 5 改為 8 以外，空格內其他數(shù)字均與 示例1 相同。

但由于位于左上角的 3x3 宮內有兩個 8 存在, 因此這個數(shù)獨是無效的。

說明:

1.一個有效的數(shù)獨（部分已被填充）不一定是可解的。
2.只需要根據(jù)以上規(guī)則，驗證已經填入的數(shù)字是否有效即可。
3.給定數(shù)獨序列只包含數(shù)字 1-9 和字符 ‘.' 。
4.給定數(shù)獨永遠是 9x9 形式的。

<script>
var isValidSudoku = function(board) {
 const boxes = [{}, {}, {}, {}, {}, {}, {}, {}, {}];
 const cols = [{}, {}, {}, {}, {}, {}, {}, {}, {}];
 const rows = [{}, {}, {}, {}, {}, {}, {}, {}, {}];
 let test = [{}, {}, {}, {}, {}, {}, {}, {}, {}];
 for (let i = 0; i < 9; i++) {
  for (let j = 0; j < 9; j++) {
   const digit = board[i][j];
   if (digit !== '.') {
    const k = Math.floor(j / 3) + (Math.floor(i / 3) * 3);
    if (boxes[k][digit] || cols[j][digit] || rows[i][digit]) {
     return false;
    }
    boxes[k][digit] = cols[j][digit] = rows[i][digit] = true;
   }
  }
 }
 return true;
};
const board = [
 ["5","3",".",".","7",".",".",".","."],
 ["6",".",".","1","9","5",".",".","."],
 [".","9","8",".",".",".",".","6","."],
 ["8",".",".",".","6",".",".",".","3"],
 ["4",".",".","8",".","3",".",".","1"],
 ["7",".",".",".","2",".",".",".","6"],
 [".","6",".",".",".",".","2","8","."],
 [".",".",".","4","1","9",".",".","5"],
 [".",".",".",".","8",".",".","7","9"]
]
console.log(isValidSudoku(board))
</script>

使用在線HTML/CSS/JavaScript代碼運行工具：http://tools.jb51.net/code/HtmlJsRun測試上述代碼，可得如下運行結果：

更多關于JavaScript相關內容感興趣的讀者可查看本站專題：《JavaScript數(shù)學運算用法總結》、《JavaScript數(shù)據(jù)結構與算法技巧總結》、《JavaScript數(shù)組操作技巧總結》、《JavaScript排序算法總結》、《JavaScript遍歷算法與技巧總結》、《JavaScript查找算法技巧總結》及《JavaScript錯誤與調試技巧總結》

希望本文所述對大家JavaScript程序設計有所幫助。