36、Valid Sudoku

题目

代码如下：

1 class Solution { 2 public: 3     bool isValidSudoku(vector
     
      
        > &board) { 4         // Note: The Solution object is instantiated only once. 5         vector
       
        
         > rows(9, vector
         
          (9,false)); 6         vector
          
           
            > cols(9, vector
            
             (9,false)); 7 vector
             
              
               > blocks(9, vector
               
                (9,false)); 8 9 for(int i = 0; i < 9; i++)10 for(int j = 0; j < 9; j++)11 {12 if(board[i][j] == '.')continue;13 int num = board[i][j] - '1';14 if(rows[i][num] || cols[j][num] || blocks[i - i%3 + j/3][num])15 return false;16 rows[i][num] = cols[j][num] = blocks[i - i%3 + j/3][num] = true;17 }18 return true;19 }20 };
               
              
             
            
           
          
         
        
       
      
     

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38、Count and Say

题目

找规律题目，直接上代码：

1 class Solution { 2 public: 3    string unguarded_convert(const string &say) 4 { 5     stringstream ss; 6     int count = 0; 7     char last = say[0]; 8      9     for (size_t i = 0; i <= say.size(); ++i)10     {11         if (say[i] == last)12         {13             ++count;14         }15         else16         {17             ss << count << last;18             count = 1;19             last = say[i];20         }21     }22     23     return ss.str();24 }25  26 string countAndSay(int n) 27 {28     if (n <= 0) return string();29     30     string say = "1";31     32     for (int i = 1; i < n; ++i)33     {34         say = unguarded_convert(say);35     }36     37     return say;38 }39 };