来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/valid-sudoku
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题目
判断一个 9x9 的数独是否有效。只需要根据以下规则，验证已经填入的数字是否有效即可。
数字 1-9 在每一行只能出现一次。
数字 1-9 在每一列只能出现一次。
数字 1-9 在每一个以粗实线分隔的 3x3 宫内只能出现一次。
image.png
上图是一个部分填充的有效的数独。
数独部分空格内已填入了数字，空白格用 '.' 表示。
示例 1:
输入:
[
["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"]
]
输出: true
示例 2:
输入:
[
["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"]
]
输出: false
解释: 除了第一行的第一个数字从 5 改为 8 以外，空格内其他数字均与 示例1 相同。
但由于位于左上角的 3x3 宫内有两个 8 存在, 因此这个数独是无效的。
说明:
一个有效的数独（部分已被填充）不一定是可解的。
只需要根据以上规则，验证已经填入的数字是否有效即可。
给定数独序列只包含数字 1-9 和字符 '.' 。
给定数独永远是 9x9 形式的。
方法1:查找横的、竖的、九宫格是否有重复
func isValidSudoku(_ board: [[Character]]) -> Bool {
for i in 0.. Bool {
//判断行row
let currentRowLine = board[row]
var boardDic = [Character: Int]()
for character in currentRowLine {
if character == "." {
continue
}
if boardDic[character] == 1 {
return false
}
boardDic[character] = 1
}
return true
}
func isValidLine(_ board: [[Character]], _ line: Int) -> Bool {
//判断列line
var boardDic = [Character: Int]()
for characterArr in board {
if characterArr[line] == "." {
continue
}
if boardDic[characterArr[line]] == 1 {
return false
}
boardDic[characterArr[line]] = 1
}
return true
}
func isValidSquare(_ board: [[Character]], _ row: Int, _ line: Int) -> Bool {
var boardDic = [Character: Int]()
//判断此九宫格
boardDic = [Character: Int]()
for i in row...row+2 {
for j in line...line+2 {
if board[i][j] == "." {
continue
}
if boardDic[board[i][j]] == 1 {
return false
}
boardDic[board[i][j]] = 1
}
}
return true
}