BitSum

BitCalculator.java

package com.davide;


/*
# funzione sommabit: effettua somme di bit ricorsivamente. Vuole in input: il primo numero da sommare, il secondo numero da sommare, il riporto al passo precedente e la posizione a cui stiamo sommando

def sommabit(a, b, riportoprecedente, posizione):
  if posizione == 0:
    s = (not (a) and b) or (a and not (b))
    r = a and b
    return s, r, 0
  elif posizione == 1:
    s = ((not (a)) and (not (b)) and riportoprecedente) or ((not (a)) and (b) and (not (riportoprecedente))) or (a and (not (b))and (not (riportoprecedente))) or (a and b and riportoprecedente)
    r = (b and riportoprecedente) or (a and riportoprecedente) or (a and b)
    return s, r, riportoprecedente
  else:
    s, r, riportoprecedente = sommabit(a, b, riportoprecedente, (posizione - 1))
    return s, r, riportoprecedente
 */

import java.util.BitSet;

public class BitCalculator {

    public static BitCalculatorResult sum(final BitSet a, final BitSet b,  BitSet carry, Integer pos) {
        if(carry == null) {
             carry = BitUtils.fromInteger(0);
        }

        if(pos == null) {
            pos = 0;
        }
        BitSet first = BitUtils.fromInteger(0);
        BitSet second = BitUtils.fromInteger(0);
        BitSet aCopyOne = (BitSet)a.clone();
        BitSet bCopyOne = (BitSet)b.clone();

        BitSet aCopyTwo = (BitSet)a.clone();
        BitSet bCopyTwo = (BitSet)b.clone();

        BitSet aCopyThree = (BitSet)a.clone();
        BitSet bCopyThree = (BitSet)b.clone();

        if(pos == 0) {
            bCopyOne.andNot(aCopyOne);
            aCopyTwo.andNot(bCopyTwo);
            bCopyOne.or(aCopyOne);
            aCopyThree.and(bCopyThree);
            first = bCopyOne;
            second = aCopyThree;
        } else if (pos == 1) {

        }

        return new BitCalculatorResult(first, second, carry, pos);
    }

}

BitCalculatorResult.java

package com.davide;

import lombok.Data;

import java.util.BitSet;

@Data
public class BitCalculatorResult {
    final BitSet first;
    final BitSet second;
    final BitSet carry;
    final Integer pos;
}

BitUtils.java

package com.davide;

import java.util.BitSet;

class BitUtils {
    public static BitSet fromString(final String s) {
        return BitSet.valueOf(new long[] { Long.parseLong(s, 2) });
    }

    public static BitSet fromInteger(final Integer n) {
        return BitSet.valueOf(new long[]{n});
    }


    public static String toString(BitSet bs) {
        return Long.toString(bs.toLongArray()[0], 2);
    }
}

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.davide</groupId>
    <artifactId>bitsum</artifactId>
    <version>1.0-SNAPSHOT</version>
    <properties>
        <maven.compiler.source>1.11</maven.compiler.source>
        <maven.compiler.target>1.11</maven.compiler.target>
    </properties>
    <dependencies>
        <!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.4</version>
            <scope>provided</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-log4j12 -->
        <dependency>
            <groupId>org.slf4j</groupId>
            <artifactId>slf4j-log4j12</artifactId>
            <version>1.7.25</version>
        </dependency>
        <dependency>
            <groupId>com.jcabi</groupId>
            <artifactId>jcabi-log</artifactId>
            <version>0.17.3</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.7.0</version>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>