Write a program to solve a Sudoku puzzle by filling the empty cells.
Empty cells are indicated by the character '.'.
You may assume that there will be only one unique solution.
A sudoku puzzle...
...and its solution numbers marked in red.
class Solution {
private:
bool isValidSudoku(vector<vector<char>> & board, int row, int col,
char val) {
int N = board.size();
for (int i = ; i < N; i++) {
if (board[row][i] == val)
return false;
}
for (int i = ; i < N; i++) {
if (board[i][col] == val)
return false;
}
int r = row / * ;
int c = col / * ;
for (int i = r; i < r + ; i++) {
for (int j = c; j < c + ; j++) {
if (board[i][j] == val)
return false;
}
}
return true;
}
bool solveSudoku(vector<vector<char>>& board, int row, int col) {
int N = board.size();
if (row == N) return true;
if (col == N) return solveSudoku(board, row + , );
if (board[row][col] != '.')
return solveSudoku(board, row, col + );
for (char k = ''; k <= ''; k++) {
if (!isValidSudoku(board, row, col, k))
continue;
board[row][col] = k;
if(solveSudoku(board, row, col + ))
return true;
board[row][col] = '.';
}
return false;
}
public:
void solveSudoku(vector<vector<char>>& board) {
solveSudoku(board, , );
}
};