标签：数字 示例 int 37 board new 解数 数独

https://leetcode-cn.com/problems/sudoku-solver/

难度困难936收藏分享切换为英文接收动态反馈

编写一个程序，通过填充空格来解决数独问题。

数独的解法需 遵循如下规则：

1. 数字 1-9 在每一行只能出现一次。
2. 数字 1-9 在每一列只能出现一次。
3. 数字 1-9 在每一个以粗实线分隔的 3x3 宫内只能出现一次。（请参考示例图）

数独部分空格内已填入了数字，空白格用 '.' 表示。

示例：

输入：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"]]
输出：[["5","3","4","6","7","8","9","1","2"],["6","7","2","1","9","5","3","4","8"],["1","9","8","3","4","2","5","6","7"],["8","5","9","7","6","1","4","2","3"],["4","2","6","8","5","3","7","9","1"],["7","1","3","9","2","4","8","5","6"],["9","6","1","5","3","7","2","8","4"],["2","8","7","4","1","9","6","3","5"],["3","4","5","2","8","6","1","7","9"]]
解释：输入的数独如上图所示，唯一有效的解决方案如下所示：

提示：

• board.length == 9
• board[i].length == 9
• board[i][j] 是一位数字或者 '.'
• 题目数据 保证 输入数独仅有一个解

通过次数97,696提交次数145,663

class Solution {
    int [][] line = new int[9][9];
    int [][] column = new int[9][9];
    int [][][] block = new int[3][3][9];
    boolean valid = false;
    List<int[]> blank = new ArrayList<int[]>();
    public void solveSudoku(char[][] board) {

        for(int i=0;i<9;i++)
        {
            for(int j=0;j<9;j++)
            {
                if(board[i][j]=='.')
                {
                    blank.add(new int[]{i,j});
                }
                else
                {
                    int x = board[i][j]-'0'-1;
                    line[i][x] = column[j][x] = block[i/3][j/3][x]=1;
                }
            }
        }
        dfs(board, 0);
    }

    void dfs(char[][] board,int index)
    {
        if(index == blank.size())
        {
            valid = true;
            return; 
        }

        int[] blank_ = blank.get(index);
        int i = blank_[0];
        int j = blank_[1];
        for(int d =0 ;d < 9 && !valid;++d)
        {
            if(line[i][d]!=1 && column[j][d]!=1 && block[i/3][j/3][d]!=1)
            {
                line[i][d] = column[j][d] = block[i/3][j/3][d] = 1;
                board[i][j] = (char)(d+'0'+1);
                dfs(board,index+1);
                line[i][d] = column[j][d] = block[i/3][j/3][d] = 0;
            }
        }
    }
}

标签：数字,示例,int,37,board,new,解数,数独
来源： https://blog.csdn.net/Getugly/article/details/120169573

本站声明： 1. iCode9 技术分享网（下文简称本站）提供的所有内容，仅供技术学习、探讨和分享；
2. 关于本站的所有留言、评论、转载及引用，纯属内容发起人的个人观点，与本站观点和立场无关；
3. 关于本站的所有言论和文字，纯属内容发起人的个人观点，与本站观点和立场无关；
4. 本站文章均是网友提供，不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属；如您发现该文章侵犯了您的权益，可联系我们第一时间进行删除；
5. 本站为非盈利性的个人网站，所有内容不会用来进行牟利，也不会利用任何形式的广告来间接获益，纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。