package kata_007_二进制序列转十进制int;

/**

 * java8 Lambda表达式转换binary序列->十进制数

 */

import java.util.ArrayList;

public class ShortBinaryToDecimal {

    public static void main(String[] args) {

        ArrayList<Integer> binary = new ArrayList();

        binary.add(1);

        binary.add(0);

        binary.add(1);

        binary.add(0);

        int result = binaryToDecimal(binary);

        System.out.println(result);

    }

    public static int binaryToDecimal(ArrayList<Integer> binary) {

          return binary.stream().reduce((x, y) -> x * 2 + y).get();

    }

}

package kata_007_二进制序列转十进制int;

import java.awt.List;

import java.util.ArrayList;

public class TestBinaryToDecimal {

    public static void main(String[] args) {

        //test method

        ArrayList binary = new ArrayList();

        binary.add(1);

        binary.add(0);

        binary.add(0);

        binary.add(1);

        int result = binaryToDecimal(binary);

        System.out.println(result);

    }

    public static int binaryToDecimal(ArrayList<Integer> binary) {

        String binaryStr = "";

        for(int i=0;i<binary.size();i++) {

            binaryStr += binary.get(i);

        }

        //String binary -> String decimal

        String decimalStr = Integer.valueOf(binaryStr,2).toString();

        //String decimal -> int

        int decimalResult = Integer.parseInt(decimalStr);

        return decimalResult;

    }

}