[LeetCode][JavaScript]Valid Sudoku

標籤：

https://leetcode.com/problems/valid-sudoku/

Valid Sudoku

Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules.

The Sudoku board could be partially filled, where empty cells are filled with the character ‘.‘.

A partially filled sudoku which is valid.

 

Note:
A valid Sudoku board (partially filled) is not necessarily solvable. Only the filled cells need to be validated.

 

 

正好用了一下最近get的新姿勢，沒有用map存1-9是否訪問過。

一個變數_bit就記下了這新資訊，用位元運算。

比如來的數是4，就是100，與_bit做位與，如果沒有出現過100&000是0，否則100&100不等於0，最後用100|000記下4已經訪問過了。

人蔘第一次使用四重迴圈。這種酸爽不敢相信，我用腳趾猜row，column，square這3種情況可以合并，但是為了紀念我人生的第一次四重迴圈，就這樣吧(其實是懶。

 1 /** 2  * @param {character[][]} board 3  * @return {boolean} 4  */ 5 var isValidSudoku = function(board) { 6     this._bit = 0; 7     function isValid(num){ 8         var tmp = Math.pow(2, num - 1); 9         if((this._bit & tmp) !== 0){10             return false;11         }else{12             this._bit = this._bit | tmp;13             return true;14         }15     }16     17     var i = 0, j = 0, m = 0, n =0, cell = 0;18     //row19     for(i = 0; i < 9; i++){20         for(j = 0; j < 9; j++){21             cell = parseInt(board[i][j]);22             if(!isValid(cell)){23                 return false;24             }25         }26         this._bit = 0;27     }28     //column29     for(i = 0; i < 9; i++){30         for(j = 0; j < 9; j++){31             cell = parseInt(board[j][i]);32             if(!isValid(cell)){33                 return false;34             }35         }36         this._bit = 0;37     }38     //square39     for(i = 0; i <= 6; i+=3){40         for(j = 0; j <=6 ; j+=3){41             for(m = 0; m < 3; m++){42                 for(n = 0; n < 3; n++){43                     cell = parseInt(board[m + i][n + j]);44                     if(!isValid(cell)){45                         return false;46                     }47                 }48             }49             this._bit = 0;50         }51     }52     return true;53 };

 

 

[LeetCode][JavaScript]Valid Sudoku