Hello everyone! Could you please help me with this problem:

this code getting a Runtime error although in my compiler it is working good.

My first thought was that it is because I was using "Character.getNumericValue" function, but this was the wrong assumption. Any ideas? Thank you in advance.

I already tried to apply static modifiers, after that I tried to exclude any static functions from any classes (like Character).

In my own IDE it works FINE in any way...

(the problem name is "Valid Sudoku")

```
class Solution {
public int size=9;
public boolean isValidInRow(char[] row){
boolean[] digits=new boolean[size];
for (int i=0; i<row.length; ++i){
//int v=Character.getNumericValue(row[i]);
int v=row[i]-'0';
if (v==-1 || v==-2) continue;
//if (v==-2) continue;
if (digits[v]){
return false;
} else
digits[v]=true;
}
return true;
}
public boolean isValidInColumn(char[][] array, int ncol){
char[] col=new char[size];
for (int i=0; i<size;++i ){
col[i]=array[i][ncol];
}
return isValidInRow(col);
}
public boolean isValidInSquare(char[][] array, int x, int y){
char[] a=new char[size];
for (int i=0; i<3;++i)
for (int j=0; j<3; ++j)
a[3*i+j]=array[x+i][y+j];
return isValidInRow(a);
}
public boolean isValidSudoku(char[][] board) {
for (int i=0; i<size;++i){
boolean b=isValidInRow(board[i]) && isValidInColumn(board,i);
if (!b) return false;
}
for (int i=0; i<size; i+=3){
for (int j=0; j<size; j+=3){
boolean b=isValidInSquare(board, i, j);
if (!b) return false;
}
}
return true;
}
}
```