Leetcode 36. 有效的数独(可以,一次过)_实线


请你判断一个 9 x 9 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。

  1. 数字 1-9 在每一行只能出现一次。
  2. 数字 1-9 在每一列只能出现一次。
  3. 数字 1-9 在每一个以粗实线分隔的 3x3 宫内只能出现一次。(请参考示例图)

注意:

  • 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。
  • 空白格用 '.' 表示。

示例 1:

Leetcode 36. 有效的数独(可以,一次过)_i++_02

输入:board = 
[["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:board = 
[["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。

提示:

  • board.length == 9
  • board[i].length == 9
  • board[i][j] 是一位数字(1-9)或者 '.'

主要思路:map
Code:

class Solution {
public:
bool isValidSudoku(vector<vector<char>>& board) {
map<char,int>mymap;
pair<map<char, int>::iterator, bool> ret;
for(int j=0;j<board[0].size();j++)
{
for(int i=0;i<board.size();i++)
{
vector<char>sub=board[i];
if(board[i][j]=='.')
continue;
ret=mymap.insert(pair<char,int>(board[i][j],0));
if(!ret.second)
return false;
cout<<board[i][j]<<endl;
}
mymap.clear();
}
mymap.clear();
for(int i=0;i<board.size();i++)
{
vector<char>sub=board[i];
for(int j=0;j<sub.size();j++)
{
if(sub[j]=='.')
continue;
ret=mymap.insert(pair<char,int>(sub[j],0));
if(!ret.second)
return false;
}
mymap.clear();
}
mymap.clear();
cout<<"++++"<<endl;
int row=0;
int col=0;
do
{

for(int i=row;i<row+3;i++)
{
vector<char>sub=board[i];
for(int j=col;j<col+3;j++)
{
if(sub[j]=='.')
continue;
ret=mymap.insert(pair<char,int>(sub[j],0));
if(!ret.second)
return false;
}
}
col+=3;
mymap.clear();
if(col==9)
{
col=0;
row+=3;
cout<<"row="<<row<<endl;
}
if(row==9)
{
break;
}
}while(1);

return true;

}
};