32 - Valid Sudoku

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.

solution：空间换时间，设置多个二维数组分别记录横，纵，块中九个数字的出现次数，若重复出现则报错，反之该数独是valid的。

PS: 还需要判断数是否在1-9之间，若超出该范围也是错误的。

class Solution {public:    bool isValidSudoku(vector<vector<char> > &board) {        // Note: The Solution object is instantiated only once and is reused by each test case.        int si = board[0].size();        if(si <= 0)            return false;                vector< vector<bool> >rows(si,vector<bool>(si,false));        vector< vector<bool> >cols(si,vector<bool>(si,false));        vector< vector<bool> >blocks(si,vector<bool>(si,false));                for(int row = 0; row < si; row++)        {            for(int col = 0; col < si; col++)            {                char temp = board[ row ][ col ];                if(temp == '.')                    continue;                int num = temp - '1';                if( rows[ row ][ num ] || cols[ col ][ num ] || blocks[ col/3 + row - row % 3 ][ num ] )                    return false;                                rows[ row ][ num ] = true;                cols[ col ][ num ] = true;                blocks[ col/3 + row - row % 3 ][ num ] = true;            }        }        return true;    }};