if (decimalNumber <= 0) { return ""; } String binary = ""; while (decimalNumber > 0) { binary = decimalNumber % 2 + binary; decimalNumber = decimalNumber / 2; } return binary; } public static int toDecimal(String binaryNumber) { //напишите тут ваш код int decimal = 0; if(binaryNumber == null){ return decimal; } for (int i = 0; i < binaryNumber.length(); i++) { decimal = (int) ((Character.getNumericValue(binaryNumber.charAt(i- 1))) * Math.pow(2,i)) + decimal; } return decimal; } }