public static boolean chkCol(char[][] arr,int col){
		boolean res = true;
		Set<Character> set = new HashSet<>();
		for(int i=0;i<arr.length;i++){
			if(arr[i][col]!='.') {
				if (set.contains(arr[i][col])) {
					if(log){
						prints(set);
						System.out.println("i "+i+",col "+col+","+arr[i][col]);
					}
					res = false;
					break;
				} else {
					set.add(arr[i][col]);
				}
			}
		}
		return res;
	}