Leetcode || Valid Sudoku

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 ‘.’.

public class Solution {
  static HashMap<Character, Integer> map = new HashMap<Character, Integer>();

    public void initMap() {
        for(char i='0'; i<='9'; i++)