LeetCode Sudoku Solver

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...



题意：数独游戏
思路：回溯解决，是不是好久没写了，开标记数组老是错

class Solution {
	public:
		bool check(vector<vector<char> > &board, int position) {
			int x = position / 9;
			int y = position % 9;
			for (int i = 0; i < 9; i++)  
				if (i != x && board[i][y] == board[x][y])  
					return false;  
			for (int j = 0; j < 9; j++)  
				if (j != y && board[x][j] == board[x][y])  
					return false;  
			for (int i = x / 3 * 3; i < (x / 3 + 1) * 3; i++)  
				for (int j = y / 3 * 3; j < (y / 3 + 1) * 3; j++)  
					if (i != x && j != y && board[i][j] == board[x][y])  
						return false;  
			return true;  
		}

		bool solve(vector<vector<char> > &board, int position) {
			if (position == 81)
				return true;

			int row = position / 9;
			int col = position % 9;
			if (board[row][col] == '.') {
				for (int i = 1; i <= 9; i++) {
					board[row][col] = i + '0';
					if (check(board, position) && solve(board, position+1))
						return true;
					board[row][col] = '.';
				}
			}
			else {
				if (solve(board, position + 1))
					return true;
			}
			return false;
		}

		void solveSudoku(vector<vector<char> > &board) {
			solve(board, 0);
		}
};