LeetCode Valid Sudoku

Description

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.

The original problem is here.

The original code is here.

My Solution

I solve this problem in C++, as below:

/*
*Valid Sudoku
*Author: shuaijiang
*Email: zhaoshuaijiang8@gmail.com
*/
#include<iostream>
#include<stdlib.h>
using namespace std;

class Solution {
public:
    bool isValidSudoku(vector<vector<char>>& board) {
        for(int row=0;row<board.size();row++){
            if(!isValid(board,row,row,0,board[row].size()-1))
                return false;
        }
        for(int col=0;col<board[0].size();col++){
            if(!isValid(board,0,board.size()-1,col,col))
                return false;
        }
        for(int row=0;row<board.size();row+=3){
            for(int col=0;col<board[0].size();col+=3){
                if(!isValid(board,row,row+2,col,col+2))
                    return false;
            }
        }
        return true;
    }
    bool isValid(vector<vector<char>>& board, int rowi, int rowj, int coli, int colj) {
        int index[10]={0};
        int num;
        for(int row=rowi;row<=rowj;row++){
            for(int col=coli;col<=colj;col++){
                if(board[row][col]!='.'){
                    num = board[row][col] - '0';
                    index[num] += 1;
                    if(index[num] > 1)
                        return false;
                }
            }
        }
        return true;
    }
};

Note

To solve the problem, just check whether each row(each column, each 3*3 area) has repeat digitals resoectively.