Leetcode 36 Valid Sudoku

本文介绍了一种高效算法,用于验证9x9数独盘面是否符合数独的基本规则,包括行、列及3x3子网格内数字1-9不重复。通过使用HashSet进行快速查找,确保了算法的时间复杂度为O(n^2),适用于部分填充的数独盘面。

摘要生成于 C知道 ,由 DeepSeek-R1 满血版支持, 前往体验 >

Determine if a 9x9 Sudoku board is valid. Only the filled cells need to be validated according to the following rules:

  1. Each row must contain the digits 1-9 without repetition.
  2. Each column must contain the digits 1-9 without repetition.
  3. Each of the 9 3x3 sub-boxes of the grid must contain the digits 1-9 without repetition.


A partially filled sudoku which is valid.

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

Example 1:

Input:
[
  ["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"]
]
Output: true

Example 2:

Input:
[
  ["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"]
]
Output: false
Explanation: Same as Example 1, except with the 5 in the top left corner being 
    modified to 8. Since there are two 8's in the top left 3x3 sub-box, it is invalid.

Note:

  • A Sudoku board (partially filled) could be valid but is not necessarily solvable.
  • Only the filled cells need to be validated according to the mentioned rules.
  • The given board contain only digits 1-9 and the character '.'.
  • The given board size is always 9x9.

这个题的意思是判断目前已知的九宫格中是否符合规则,使用一个HashMap或者是Set即可解决。

1)

class Solution {
    public boolean isValidSudoku(char[][] board) {
        Set seen = new HashSet();
        for (int i=0; i<9; ++i) {
            for (int j=0; j<9; ++j) {
                if (board[i][j] != '.') {
                    String b = "(" + board[i][j] + ")";
                    if (!seen.add(b + i) || !seen.add(j + b) || !seen.add(i/3 + b + j/3))
                        return false;
                }
            }
        }
        return true;
    }
}

时间复杂度O(n2)

2)

class Solution {
    public boolean isValidSudoku(char[][] board) {
    for(int i = 0; i < board.length; i++) {
        if (!isRowValid(board, i) || !isColumnValid(board, i)) {
            return false;
    }		
    } 
    for (int i = 0; i < board.length; i+=3) {
        for(int j = 0; j < board.length; j+=3) {
            if (!isSquareValid(board,i, j)) {
                return false;
            }
        }
    }
    return true;
    }

    public boolean isSquareValid(char[][] board, int iStart, int jStart) {
        Set<Integer> set = new HashSet<>();
        for (int i = iStart; i < iStart + 3; i++) {
            for (int j = jStart; j < jStart + 3; j++) {
            if (board[i][j] != '.' && !set.add(board[i][j] - '.')) {
                return false;
            }
            }
        }
        return true;
    }

    public boolean isRowValid(char[][] board, int index) {
        Set<Integer> set = new HashSet<>();
        for(int i = 0; i < board.length; i++) {
            if (board[index][i] != '.' && !set.add(board[index][i] - '.')) {
                return false;
            }
        }
        return true;
    }
    public boolean isColumnValid(char[][] board, int index) {
        Set<Integer> set = new HashSet<>();
        for(int i = 0; i < board.length; i++) {
            if (board[i][index] != '.' && !set.add(board[i][index] - '.')) {
                return false;
            }
        }
        return true;

    }

}

 

资源下载链接为: https://pan.quark.cn/s/22ca96b7bd39 在当今的软件开发领域,自动化构建与发布是提升开发效率和项目质量的关键环节。Jenkins Pipeline作为一种强大的自动化工具,能够有效助力Java项目的快速构建、测试及部署。本文将详细介绍如何利用Jenkins Pipeline实现Java项目的自动化构建与发布。 Jenkins Pipeline简介 Jenkins Pipeline是运行在Jenkins上的一套工作流框架,它将原本分散在单个或多个节点上独立运行的任务串联起来,实现复杂流程的编排与可视化。它是Jenkins 2.X的核心特性之一,推动了Jenkins从持续集成(CI)向持续交付(CD)及DevOps的转变。 创建Pipeline项目 要使用Jenkins Pipeline自动化构建发布Java项目,首先需要创建Pipeline项目。具体步骤如下: 登录Jenkins,点击“新建项”,选择“Pipeline”。 输入项目名称和描述,点击“确定”。 在Pipeline脚本中定义项目字典、发版脚本和预发布脚本。 编写Pipeline脚本 Pipeline脚本是Jenkins Pipeline的核心,用于定义自动化构建和发布的流程。以下是一个简单的Pipeline脚本示例: 在上述脚本中,定义了四个阶段:Checkout、Build、Push package和Deploy/Rollback。每个阶段都可以根据实际需求进行配置和调整。 通过Jenkins Pipeline自动化构建发布Java项目,可以显著提升开发效率和项目质量。借助Pipeline,我们能够轻松实现自动化构建、测试和部署,从而提高项目的整体质量和可靠性。
评论
添加红包

请填写红包祝福语或标题

红包个数最小为10个

红包金额最低5元

当前余额3.43前往充值 >
需支付:10.00
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值