# Leetcode 36 Valid Sudoku.

Leetcode 36 Valid Sudoku

etermine 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.

Thought the system shows that this problem is a easy one, but if you want to write it correct is not so easy.

``````
public class Solution {
public boolean isValidSudoku(char[][] board) {
for(int i=0;i < 9;i++){
if(!ispartialvalid(board,i,0,i,8)){
return false;
}
if(!ispartialvalid(board,0,i,8,i)){
return false;
}

}
for(int j=0;j < 3;j++){
for(int i=0;i < 3;i++){
if(!ispartialvalid(board,3*j,3*i,3*(j+1)-1,3*(i+1)-1)){
return false;
}
}

}
return true;
}

public boolean ispartialvalid(char[][] board,int x1,int y1,int x2, int y2){
HashSet myhash=new HashSet();
for(int i=x1;i < =x2;i++){
for(int j=y1;j < =y2;j++){
if(board[i][j]!='.'){