有效的数独

To be clear , I am unable to do so...

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.

Example

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

160 ms

class Solution {
    func isValidSudoku(_ board: [[Character]]) -> Bool {
        var rowNums = Array(repeating: 0, count: 9)
        var colNums = Array(repeating: 0, count: 9)
        var boxNums = Array(repeating: 0, count: 9)
        
        for i in 0..<9 {
            for j in 0..<9 {
                if !board[i][j].isNumber {
                    continue
                }
                let num = board[i][j].wholeNumberValue ?? 0
                
                if rowNums[i] & 1 << num != 0 {
                    return false
                } else {
                    rowNums[i] |= 1 << num
                }
                
                if colNums[j] & 1 << num != 0{
                    return false
                } else {
                    colNums[j] |= 1 << num
                }
                
                let boxIndex = i / 3 * 3 + j / 3
                if boxNums[boxIndex] & 1 << num != 0 {
                    return false
                } else {
                    boxNums[boxIndex] |= 1 << num
                }
            }
        }
        return true
    }
}

Swift Continue 语句

Swift continue语句告诉一个循环体立刻停止本次循环迭代，重新开始下次循环迭代。

位运算符

位运算符用来对二进制位进行操作，~ , & , | , ^ 分别为取反，按位与与，按位与或，按位与异或运算，如下表实例：

如果指定 A = 60; 及 B = 13; 两个变量对应的二进制为：

A = 0011 1100

B = 0000 1101

Swift 正则表达式 NSRegularExpression

枚举类型

typedef NS_OPTIONS(NSUInteger, NSRegularExpressionOptions) {
        NSRegularExpressionCaseInsensitive          = 1 << 0,   // 不区分大小写的
        NSRegularExpressionAllowCommentsAndWhitespace  = 1 << 1,   // 忽略空格和# (注释符)
        NSRegularExpressionIgnoreMetacharacters        = 1 << 2,   // 整体化
        NSRegularExpressionDotMatchesLineSeparators    = 1 << 3,   // 匹配任何字符，包括行分隔符
        NSRegularExpressionAnchorsMatchLines          = 1 << 4,   // 允许^和$在匹配的开始和结束行
        NSRegularExpressionUseUnixLineSeparators      = 1 << 5,   // (查找范围为整个的话无效)
        NSRegularExpressionUseUnicodeWordBoundaries    = 1 << 6    // (查找范围为整个的话无效)
     };
     
typedef NS_OPTIONS(NSUInteger, NSMatchingOptions)  {
        NSMatchingReportProgress         = 1 << 0, //找到最长的匹配字符串后调用block回调
        NSMatchingReportCompletion       = 1 << 1, //找到任何一个匹配串后都回调一次block
        NSMatchingAnchored               = 1 << 2, //从匹配范围的开始处进行匹配
        NSMatchingWithTransparentBounds  = 1 << 3, //允许匹配的范围超出设置的范围
        NSMatchingWithoutAnchoringBounds = 1 << 4  //禁止^和$自动匹配行还是和结束
     };

哦我的天哪，太多了，今天就到这里为止吧！