Leetcode题解（十三）

36、Valid Sudoku

题目

代码如下：

 class Solution {
 public:
     bool isValidSudoku(vector<vector<char> > &board) {
         // Note: The Solution object is instantiated only once.
         vector<vector<bool>> rows(, vector<bool>(,false));
         vector<vector<bool>> cols(, vector<bool>(,false));
         vector<vector<bool>> blocks(, vector<bool>(,false));

         for(int i = ; i < ; i++)
             for(int j = ; j < ; j++)
             {
                 if(board[i][j] == '.')continue;
                 int num = board[i][j] - '';
                 if(rows[i][num] || cols[j][num] || blocks[i - i% + j/][num])
                     return false;
                 rows[i][num] = cols[j][num] = blocks[i - i% + j/][num] = true;
             }
         return true;
     }
 };

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38、Count and Say

题目

找规律题目，直接上代码：

 class Solution {
 public:
    string unguarded_convert(const string &say)
 {
     stringstream ss;
     int count = ;
     char last = say[];

     for (size_t i = ; i <= say.size(); ++i)
     {
         if (say[i] == last)
         {
             ++count;
         }
         else
         {
             ss << count << last;
             count = ;
             last = say[i];
         }
     }

     return ss.str();
 }

 string countAndSay(int n)
 {
     if (n <= ) return string();

     string say = "";

     for (int i = ; i < n; ++i)
     {
         say = unguarded_convert(say);
     }

     return say;
 }
 };