LeetCode 36 Valid Sudoku

Problem:

Determine if a Sudoku is valid, according to: Sudoku Puzzles - The Rules.

The Sudoku board could be partially filled, where empty cells are filled with the character '.'.

A partially filled sudoku which is valid.

Note:
A valid Sudoku board (partially filled) is not necessarily solvable. Only the filled cells need to be validated.

Summary:

判断当前给出的数独是否满足条件。

Solution:

横向，纵向，每个3*3小方格分别判断。

class Solution {
public:
    bool isValidSudoku(vector<vector<char>> board) {
        int validRow[9] = { 0 }, validCol[9] = { 0 };
        int validSqr[9] = { 0 };
    
        for (int i = 0; i < 9; i++) {
            memset(validRow, 0, sizeof(validRow));
            memset(validCol, 0, sizeof(validCol));
    
            for (int j = 0; j < 9; j++) {
                if (board[i][j] != '.') {
                    char tmp = board[i][j];
                    if (!validRow[tmp - '0' - 1]) {
                        validRow[tmp - '0' - 1]++;
                    }
                    else {
                        return false;
                    }
                }
    
                if (board[j][i] != '.') {
                    char tmp = board[j][i];
                    if (!validCol[tmp - '0' - 1]) {
                        validCol[tmp - '0' - 1]++;
                    }
                    else {
                        return false;
                    }
                }
            }
        }
    
        for (int m = 0; m < 3; m++) {
            for (int n = 0; n < 3; n++) {
                memset(validSqr, 0, sizeof(validSqr));
    
                for (int i = m * 3; i < m * 3 + 3; i++) {
                    for (int j = n * 3; j < n * 3 + 3; j++) {
                        if (board[i][j] != '.') {
                            char tmp = board[i][j];
                            if (!validSqr[tmp - '0' - 1]) {
                                validSqr[tmp - '0' - 1]++;
                            }
                            else {
                                return false;
                            }
                        }
    
                    }
                }
            }
        }
    
        return true;
    }

};