Java：在链表中添加数字会产生奇怪的结果

我必须编写一个程序，在LinkedList数组中存储多达10个任意长的数字，然后将它们相加，存储在第11个列表中，然后输出结果。我已经写了所有的代码，但是当我打印结果时，我得到了不可靠的结果。这是我的密码：

import java.util.*;

public class LongNumbers {

   private List<Integer> [] theLists;

   public LongNumbers(){
   this.theLists = new LinkedList[11];
   for (int i=0; i<11; i++)
   this.theLists[i]= new LinkedList<>();
}

public void add(int location, int digit)
{
//add digit at head of LinkedList given by location
theLists[location].add(digit);
}
public int remove(int location)
{
//remove a digit from LinkedList given by location
    return theLists[location].remove(location);
}
public boolean isEmpty(int location)
{
//check for an empty LinkedList given by location
return theLists[location].isEmpty();
}

public static void main(String[] args)
{
Scanner kb = new Scanner(System.in);

//local variables
String number;
boolean userWantsToQuit = false;
LongNumbers lists = new LongNumbers();
int currArrayLocation = 0;
int currDigit = 0;
int maxLength = 0;
int numsEntered = 0;
int finalDigit = 0;
int carryDigit = 0;
char[] digits;

//get data
do{
System.out.println("Enter a number, or enter -1 to escape.");
number = kb.nextLine();

if(number.equals("-1"))
    userWantsToQuit = true;
else {
    numsEntered++;
    if (number.length()> maxLength) 
        maxLength = number.length();
    digits = new char[number.length()]; 
    for (int i = 0; i < number.length(); i++){
        digits[i] = number.charAt(i);
        currDigit = digits[i]-48;
        lists.add(currArrayLocation, currDigit);}
    } 
    currArrayLocation++;

} while (!userWantsToQuit && currArrayLocation < 9 );
//if the linkedLists are full
if (currArrayLocation == 9)
    System.out.println("The max amount of numbers have been entered.");

//to add numbers into final linked list
for (int i = 0; i < maxLength; i++){
    for (currArrayLocation = 0; currArrayLocation < numsEntered; currArrayLocation++){
       if (lists.theLists[currArrayLocation]== null){
            lists.remove(0);}
            //currDigit = 0;
       else{
            currDigit = lists.theLists[currArrayLocation].get(0);
        int tempDigit = currDigit;
        System.out.println("temp: " + tempDigit); //test line
        finalDigit += tempDigit;
        System.out.println(finalDigit); //test line
        }



    //add the proper digit to the last LinkedList and set carry digit
    finalDigit = finalDigit + carryDigit;
    carryDigit = finalDigit/10;
    //lists.add(10, finalDigit);
    //lists.remove(0); 
    //finalDigit = 0;       
} 
lists.add(10, finalDigit);
lists.remove(0);
finalDigit = 0;   
}
//print the sum
if (lists.theLists[10] != null){
        System.out.print("Sum: ");
        for (int i = 0; i < lists.theLists[10].size() ; i++){
        System.out.print(lists.theLists[10].get(i));
        }
    }
}//end main
}//end class        

import java.util.*；
公共类长号码{
私人名单[]个人名单；
公众电话号码（）{
this.theLists=新链接列表[11]；
对于（int i=0；i maxLength）
maxLength=number.length（）；
数字=新字符[number.length（）]；
对于（int i=0；i

当我把100和200加起来，得到322。我认为我的问题在于注释//后面的几行将数字添加到最终的链表中

---

任何见解或想法都会很棒，提前谢谢

是的，这个确实有很多问题

我将您的代码通过BlueJ的调试器，经过痛苦的调试，我终于发现了问题。很快我就意识到你的第81行应该是：

currDigit = lists.theLists[currArrayLocation].get(i);

但是如果你这样做，你会得到一个

索引自动边界异常

，这让我困惑了一段时间，但我最终发现了有问题的第97行：

lists.remove(0);

这让我发现您的

公共int-remove（int-location）

方法完全错误。它所做的唯一一件事就是删除你其中一个号码中的一个数字。我想你的意思是这样的：

public void remove(int location)
{
    //remove a digit from LinkedList given by location
    for (int i=0; i<theLists[location].size(); i++){
        theLists[location].remove(i);
        theLists[location].add(i,0);
    }
}

public static void bufferWithLeadingZeroes(List<Integer>[] theLists, int maxLength){
    for (int i=0; i<10; i++){
        int howManyToAdd = maxLength - theLists[i].size();
        for (int j=0; j<howManyToAdd; j++){
            theLists[i].add(0,0);
        }
    }
    theLists[10].add(0,0);
}

但是，像往常一样，这又引起了另一个问题。当将不同长度的数字相加时，我们在第81行（我们之前修复的那行）上得到另一个

IndexOutOfBoundsException

。结果表明，这是由顶部循环造成的，该循环假定输入的每个数字都具有相同的长度。为了解决这个问题，我写了一个方法，在所有数字的开头输入前导零，如下所示：

public void remove(int location)
{
    //remove a digit from LinkedList given by location
    for (int i=0; i<theLists[location].size(); i++){
        theLists[location].remove(i);
        theLists[location].add(i,0);
    }
}

public static void bufferWithLeadingZeroes(List<Integer>[] theLists, int maxLength){
    for (int i=0; i<10; i++){
        int howManyToAdd = maxLength - theLists[i].size();
        for (int j=0; j<howManyToAdd; j++){
            theLists[i].add(0,0);
        }
    }
    theLists[10].add(0,0);
}

所以现在，最后，吸盘起作用了。以下是（节略）输出：

您会注意到，Sum是用前导零打印的。您可能需要更改打印数字的最终循环，以便它可以修剪这些数字

---

最后，这里是我们完整的工作代码：

    import java.util.*;

public class LongNumbers {

    private List<Integer> [] theLists;

    public LongNumbers(){
        this.theLists = new LinkedList[11];
        for (int i=0; i<11; i++)
            this.theLists[i]= new LinkedList<>();
    }

    public void add(int location, int digit)
    {
        //add digit at head of LinkedList given by location
        theLists[location].add(digit);
    }

    public void remove(int location)
    {
        //remove a digit from LinkedList given by location
        for (int i=0; i<theLists[location].size(); i++){
            theLists[location].remove(i);
            theLists[location].add(i,0);
        }
    }

    public boolean isEmpty(int location)
    {
        //check for an empty LinkedList given by location
        return theLists[location].isEmpty();
    }

    public static void main(String[] args)
    {
        Scanner kb = new Scanner(System.in);

        //local variables
        String number;
        boolean userWantsToQuit = false;
        LongNumbers lists = new LongNumbers();
        int currArrayLocation = 0;
        int currDigit = 0;
        int maxLength = 0;
        int numsEntered = 0;
        int finalDigit = 0;
        int carryDigit = 0;
        char[] digits;

        //get data
        do{
            System.out.println("Enter a number, or enter -1 to escape.");
            number = kb.nextLine();

            if(number.equals("-1"))
                userWantsToQuit = true;
            else {
                numsEntered++;
                if (number.length()> maxLength) 
                    maxLength = number.length();
                digits = new char[number.length()]; 
                for (int i = 0; i < number.length(); i++){
                    digits[i] = number.charAt(i);
                    currDigit = digits[i]-48;
                    lists.add(currArrayLocation, currDigit);}
            } 
            currArrayLocation++;

        } while (!userWantsToQuit && currArrayLocation < 9 );
        //if the linkedLists are full
        if (currArrayLocation == 9)
            System.out.println("The max amount of numbers have been entered.");
        bufferWithLeadingZeroes(lists.theLists,maxLength);
        //to add numbers into final linked list
        for (int i = 0; i < maxLength; i++){
            for (currArrayLocation = 0; currArrayLocation < numsEntered; currArrayLocation++){
                if (lists.theLists[currArrayLocation]== null){
                    lists.remove(0);}
                //currDigit = 0;
                else{
                    currDigit = lists.theLists[currArrayLocation].get(i);
                    int tempDigit = currDigit;
                    System.out.println("temp: " + tempDigit); //test line
                    finalDigit += tempDigit;
                    System.out.println(finalDigit); //test line
                }
            }
            if (finalDigit > 9){
                i++;
                int newDigit = lists.theLists[10].get(i-1) + (finalDigit/10);
                lists.theLists[10].remove(i-1);
                lists.theLists[10].add(i-1,newDigit);
                finalDigit %= 10;
                for (int j=(i-1); j>=0; j--){
                    if (lists.theLists[10].get(j) > 9){
                        if (j == 0){
                            lists.theLists[10].add(j,0);
                            j++;
                            i++;
                        }
                        newDigit = lists.theLists[10].get(j-1) + 1;
                        lists.theLists[10].remove(j-1);
                        lists.theLists[10].add(j-1,newDigit);
                        newDigit = lists.theLists[10].get(j) % 10;
                        lists.theLists[10].remove(j);
                        lists.theLists[10].add(j,newDigit);
                    }
                }
                i--;
            }
            lists.add(10, finalDigit);
            finalDigit = 0;
        }
        //print the sum
        if (lists.theLists[10] != null){
            System.out.print("Sum: ");
            for (int i = 0; i < lists.theLists[10].size() ; i++){
                System.out.print(lists.theLists[10].get(i));
            }
        }
    }//end main

    public static void bufferWithLeadingZeroes(List<Integer>[] theLists, int maxLength){
        for (int i=0; i<10; i++){
            int howManyToAdd = maxLength - theLists[i].size();
            for (int j=0; j<howManyToAdd; j++){
                theLists[i].add(0,0);
            }
        }
        theLists[10].add(0,0);
    }

}//end class        

import java.util.*；
公共类长号码{
私人名单[]个人名单；
公众电话号码（）{
this.theLists=新链接列表[11]；
对于（int i=0；i 9）{
i++；
int newDigit=lists.theLists[10].get（i-1）+（finaldigt/10）；
列表。列表[10]。删除（i-1）；
列表。列表[10]。添加（i-1，新数字）；
finalDigit%=10；
对于（int j=（i-1）；j>=0；j--）{
if（lists.theLists[10].get（j）>9）{
如果（j==0）{
列表[10]。添加（j，0）；
j++；
i++；
}
newDigit=列表。列表[10]。获取（j-1）+1；
列表。列表[10]。删除（j-1）；
列表。列表[10]。添加（j-1，新数字）；
newDigit=列表。列表[10]。获取（j）%10；
列表。列表[10]。删除（j）；
列表。列表[10]。添加（j，新数字）；
}
}
我--；
}
列表。添加（10，最终数字）；
finalDigit=0；
}
//打印总数
if（lists.theLists[10]！=null）{
系统输出打印（“总和：”）；
对于（int i=0；i对于（int i=0；iSo此处的目标是使用数组将一组非常大的数字相加？或者是否有指定实现的特定赋值？这是一个需要使用一组链表将数字相加的赋值@jonahhaney考虑到java.math.biginger具有更平滑的存储大数字的实现。Jonah，我非常感谢你。这是我在这个网站上见过的最彻底的答案，我非常感谢你指导我完成每一步。我的教授并不是特别有帮助，我觉得我现在真正理解了每一步的错误所在，这不是每个程序员都应该追求的目标吗为？再次感谢，并为延迟回复@JonahHaneyNo prob表示歉意
    import java.util.*;

public class LongNumbers {

    private List<Integer> [] theLists;

    public LongNumbers(){
        this.theLists = new LinkedList[11];
        for (int i=0; i<11; i++)
            this.theLists[i]= new LinkedList<>();
    }

    public void add(int location, int digit)
    {
        //add digit at head of LinkedList given by location
        theLists[location].add(digit);
    }

    public void remove(int location)
    {
        //remove a digit from LinkedList given by location
        for (int i=0; i<theLists[location].size(); i++){
            theLists[location].remove(i);
            theLists[location].add(i,0);
        }
    }

    public boolean isEmpty(int location)
    {
        //check for an empty LinkedList given by location
        return theLists[location].isEmpty();
    }

    public static void main(String[] args)
    {
        Scanner kb = new Scanner(System.in);

        //local variables
        String number;
        boolean userWantsToQuit = false;
        LongNumbers lists = new LongNumbers();
        int currArrayLocation = 0;
        int currDigit = 0;
        int maxLength = 0;
        int numsEntered = 0;
        int finalDigit = 0;
        int carryDigit = 0;
        char[] digits;

        //get data
        do{
            System.out.println("Enter a number, or enter -1 to escape.");
            number = kb.nextLine();

            if(number.equals("-1"))
                userWantsToQuit = true;
            else {
                numsEntered++;
                if (number.length()> maxLength) 
                    maxLength = number.length();
                digits = new char[number.length()]; 
                for (int i = 0; i < number.length(); i++){
                    digits[i] = number.charAt(i);
                    currDigit = digits[i]-48;
                    lists.add(currArrayLocation, currDigit);}
            } 
            currArrayLocation++;

        } while (!userWantsToQuit && currArrayLocation < 9 );
        //if the linkedLists are full
        if (currArrayLocation == 9)
            System.out.println("The max amount of numbers have been entered.");
        bufferWithLeadingZeroes(lists.theLists,maxLength);
        //to add numbers into final linked list
        for (int i = 0; i < maxLength; i++){
            for (currArrayLocation = 0; currArrayLocation < numsEntered; currArrayLocation++){
                if (lists.theLists[currArrayLocation]== null){
                    lists.remove(0);}
                //currDigit = 0;
                else{
                    currDigit = lists.theLists[currArrayLocation].get(i);
                    int tempDigit = currDigit;
                    System.out.println("temp: " + tempDigit); //test line
                    finalDigit += tempDigit;
                    System.out.println(finalDigit); //test line
                }
            }
            if (finalDigit > 9){
                i++;
                int newDigit = lists.theLists[10].get(i-1) + (finalDigit/10);
                lists.theLists[10].remove(i-1);
                lists.theLists[10].add(i-1,newDigit);
                finalDigit %= 10;
                for (int j=(i-1); j>=0; j--){
                    if (lists.theLists[10].get(j) > 9){
                        if (j == 0){
                            lists.theLists[10].add(j,0);
                            j++;
                            i++;
                        }
                        newDigit = lists.theLists[10].get(j-1) + 1;
                        lists.theLists[10].remove(j-1);
                        lists.theLists[10].add(j-1,newDigit);
                        newDigit = lists.theLists[10].get(j) % 10;
                        lists.theLists[10].remove(j);
                        lists.theLists[10].add(j,newDigit);
                    }
                }
                i--;
            }
            lists.add(10, finalDigit);
            finalDigit = 0;
        }
        //print the sum
        if (lists.theLists[10] != null){
            System.out.print("Sum: ");
            for (int i = 0; i < lists.theLists[10].size() ; i++){
                System.out.print(lists.theLists[10].get(i));
            }
        }
    }//end main

    public static void bufferWithLeadingZeroes(List<Integer>[] theLists, int maxLength){
        for (int i=0; i<10; i++){
            int howManyToAdd = maxLength - theLists[i].size();
            for (int j=0; j<howManyToAdd; j++){
                theLists[i].add(0,0);
            }
        }
        theLists[10].add(0,0);
    }

}//end class