public static void placeZeroToBegining(int[] arr){
        int count = arr.length - 1;
        for(int i = arr.length - 1; i >= 0; i--){
            if(arr[i] != 0){
                arr[count--] = arr[i];
            }
        }
        while(count >= 0) arr[count--] = 0;
    }