简单二进制加法计算器(原创)

//String转List
Arrays.asList(str.split(""))
//List转String
String.join("", list)

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * @ClassName: clacdemo
 * @Date: 2020/7/7 0007 21:10
 * @Description:
 * @Author: <achao1441470436@gmail.com>
 */
public class clacdemo {

    public static void main(String[] args) {
        String four = "00000100";
        String five = "00000101";
        System.out.println(sum(four, five));
    }

    /**
     * 加法
     *
     * @param num1
     * @param num2
     * @return
     */
    public static String sum(String num1, String num2) {
        List<String> list = new ArrayList<>();
        //异或
        list.add(xor(num1, num2));
        //与
        list.add(and(num1, num2));
        //如果 与 结果为0
        if (isZero(list.get(list.size() - 1))) {
            //return 异或 的结果
            return list.get(list.size() - 2);
        }
        //从第二步开始，重复计算
        while (true) {
            //进位
            list.add(carry(list.get(list.size() - 1)));
            //异或
            list.add(xor(list.get(list.size() - 3), list.get(list.size() - 1)));
            //与
            list.add(and(list.get(list.size() - 4), list.get(list.size() - 2)));
            //如果 与 结果为0
            if (isZero(list.get(list.size() - 1))) {
                //return 异或 的结果
                return list.get(list.size() - 2);
            }
        }
    }


    /**
     * 异或
     *
     * @param num1
     * @param num2
     * @return
     */
    public static String xor(String num1, String num2) {
        List<String> numList1 = Arrays.asList(num1.split(""));
        List<String> numList2 = Arrays.asList(num2.split(""));
        List<String> result = new ArrayList<>();
        for (int i = 0; i < numList1.size(); i++) {
            //异或 如果两者相等为0 不等为1
            if (numList1.get(i).equals(numList2.get(i))) {
                result.add("0");
            } else {
                result.add("1");
            }
        }
        return String.join("", result);
    }

    /**
     * 与
     *
     * @param num1
     * @param num2
     * @return
     */
    public static String and(String num1, String num2) {
        List<String> numList1 = Arrays.asList(num1.split(""));
        List<String> numList2 = Arrays.asList(num2.split(""));
        List<String> result = new ArrayList<>();
        for (int i = 0; i < numList1.size(); i++) {
            //与 两者为1 结果为1 否则为0
            if ("1".equals(numList1.get(i)) && "1".equals(numList2.get(i))) {
                result.add("1");
            } else {
                result.add("0");
            }
        }
        return String.join("", result);
    }

    /**
     * 判断是否全为0
     *
     * @param num
     * @return
     */
    public static Boolean isZero(String num) {
        List<String> numList = Arrays.asList(num.split(""));
        for (String tempNum : numList) {
            //判断结果是否含1，有则return false
            if ("1".equals(tempNum)) {
                return false;
            }
        }
        return true;
    }

    /**
     * 进位
     *
     * @param num
     * @return
     */
    public static String carry(String num) {
        List<String> numList = Arrays.asList(num.split(""));
        for (int i = 0; i < numList.size(); i++) {
            if ("1".equals(numList.get(i))) {
                try {
                    numList.set(i - 1, "1");
                } catch (ArrayIndexOutOfBoundsException e) {
                    System.out.println("溢出！");
                    System.exit(0);
                }
                numList.set(i, "0");
            }
        }
        return String.join("", numList);
    }
}