LeetCode *** 36. Valid Sudoku

题目：

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.

分析：

因为只是判断出现的数字是否构成一个有效的数独，那么直接判断横竖以及小正方形内的数字即可。

代码：

class Solution {
public:
bool isValidSudoku(vector<vector<char>>& board) {
int sudoku[9][9];

for(int i=0;i<9;++i)
for(int j=0;j<9;++j)
if(board[i][j]!='.')sudoku[i][j]=board[i][j]-'0';
else sudoku[i][j]=0;

bool Hflag[9]={};
bool Vflag[9]={};
bool Mflag[9]={};

for(int i=0;i<9;++i){
for(int j=0;j<9;++j){
if(sudoku[i][j]){
if(Hflag[sudoku[i][j]-1])return false;
else Hflag[sudoku[i][j]-1]=1;
}

if(sudoku[j][i]){
if(Vflag[sudoku[j][i]-1])return false;
else Vflag[sudoku[j][i]-1]=1;
}

if(sudoku[(i/3)*3+j/3][(i%3)*3+j%3]){
if(Mflag[sudoku[(i/3)*3+j/3][(i%3)*3+j%3]-1])return false;
else Mflag[sudoku[(i/3)*3+j/3][(i%3)*3+j%3]-1]=1;
}
}

for(int j=0;j<9;++j){
Hflag[j]=0;
Vflag[j]=0;
Mflag[j]=0;
}
}

return true;
}
};