36.有效的数独

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class Solution {
public:
    bool isValidSudoku(vector<vector<char>>& board) {
        int columns[9][9] = {0}, 
        rows[9][9] = {0}, 
        boxes[9][9] = {0};
        for(int r = 0; r < 9; ++r)
            for(int c = 0; c < 9; ++c)
            {
                if(board[r][c] == '.')
                    continue;
                int val = board[r][c] - 48 - 1;
                // cout << val << endl;
                int box_num = r / 3 * 3 + c / 3;
                boxes[box_num][val] += 1;
                columns[c][val] += 1;
                rows[r][val] += 1;
                if(boxes[box_num][val] > 1 ||
                columns[c][val] > 1 || rows[r][val] > 1)
                {
                    return false;
                }
            }
        return true;
    }
};

Accepted

504/504 cases passed (16 ms)

Your runtime beats 71.31 % of cpp submissions

Your memory usage beats 63.82 % of cpp submissions (9.4 MB)