C++使用备用字母加密句子(字符数组)(可能重复)

Question

我在处理项目的一部分时遇到了一些麻烦。我一直在弄乱代码，但我无法让它工作。基本上，该项目执行以下操作:

1. 输入一个词
2. 删除重复项
3. 将修改后的单词存储到备用字母表中
4. 使用那个替代字母来加密一个句子

我卡在数字 4 上了。

这是我的代码:

#include <iostream>
#include <string>

using namespace std;

void fixRepeats(char array[], int size);  //Function to remove duplicates
void fixSpaces(char array[], int size);  //Function to remove spaces
void copy(char array[], char array2[], int size);

int main()
{
    char word[25];
    char modWord[25];  //User inputted word without repeated letters
    char regAlpha[27] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    char altAlpha[27];  //Alternate alphabet created from the word
    char sentence[100];
    int lenWord;  
    int lenModWord;  
    int lenAlpha = 27;
    int lenSent; 

    cout << "Please enter a single word: ";  //Get user input

    cin >> word;

    lenWord = strlen(word);  //Get length of word

    fixRepeats(word, lenWord);  //Function call from main
    fixSpaces(word, lenWord);  //Function call from main

    lenModWord = strlen(word);  //Get length of the modified word

    copy(word, modWord, lenModWord);  //Function call from main
    copy(modWord, altAlpha, lenModWord);  //Function call from main

    for (int i = 0; i < lenAlpha; i++)
    {
        for (int j = 0; j < lenModWord; j++)
        {
            if (regAlpha[i] == altAlpha[j])
            {
                regAlpha[i++];
            }
        }

        altAlpha[lenModWord++] = regAlpha[i];
    }

    fixRepeats(altAlpha, lenAlpha);
    fixSpaces(altAlpha, lenAlpha);

    cout << "\nModified Word: " << word << endl;
    cout << "\nAlphabet------: " << regAlpha << endl;
    cout << "Encryption Key: " << altAlpha << endl;

    cin.ignore(100, '\n');

    cout << "\nPlease enter a sentence: ";  //Get user input
    cin.get(sentence, 99, '\n');

    lenSent = strlen(sentence);

    //-------------------------------#4------------------------------------

    for (int i = 0; i < lenAlpha; i++)
    {
        for (int j = 0; j < lenSent; j++)
        {
            if (altAlpha[i] == sentence[j])
            {
                sentence[j] = regAlpha[i]; 
            }
        }
    }

    //-------------------------------#4------------------------------------

    cout << "\nEncrypted message: " << sentence << endl;

    cout << endl;

    return 0;
}

void copy(char array[], char array2[], int size)
{
    for (int i = 0; i < size; i++)
    {
        array2[i] = array[i];
    }
}

void fixRepeats(char array[], int size)
{
    //Use nested loop to check each character
    for (int i = 0; i <= size; i++)
    {
        for (int j = i + 1; j <= size; j++)
        {
            if (array[i] == array[j])  //Check for duplicates
            {
                array[j] = '\0';  //Change duplicate to a null char
            }
        }
    }
}

void fixSpaces(char array[], int size)
{
    //Use nested loop to check each character
    for (int i = 0; i < size; i++)
    {
        if (array[i] == '\0')  //Check for space or null char
        {
            for (int j = i + 1; j < size; j++)
            {
                if (array[j] != '\0')  //Check the next position
                {
                    swap(array[j], array[i]);  //Swap positions
                    break;
                }
            }
        }
    }
}

我在代码中用破折号和 #4 标记了我的问题。

期望的结果是这样的:

Please enter a single word: HELLO

Modified Word: HELO

Alphabet------: ABCDEFGHIJKLMNOPQRSTUVWXYZ
Encryption Key: HELOABCDFGIJKMNPQRSTUVWXYZ

Please enter a sentence: HE IS HUMAN

Encrypted message: DA FS DUKHM

另一个使用相同词的例子是:

Please enter a sentence: COMPUTER SCIENCE

Encrypted message: LNKPUTAR SLFAMLA

Please enter a sentence: PLEASE HELP

Encrypted message: PJAHSA DAJP

当我运行我的代码时，它会变成这样:

Please enter a single word: HELLO

Modified Word: HELO

Alphabet------: ABCDEFGHIJKLMNOPQRSTUVWXYZ
Encryption Key: HELOABCDFGIJKMNPQRSTUVWXYZ

Please enter a sentence: HE IS HUMAN

Encrypted message: EO OS EUOEO

和:

Please enter a sentence: COMPUTER SCIENCE

Encrypted message: LHOPUTOR SLOOOLO

Please enter a sentence: PLEASE HELP

Encrypted message: PLOESO EOLP

其他一切都很好，只是加密部分出了问题。我也知道这是完全错误的(这更像是一次尝试)。

关于如何修复该单个部分的任何建议(假设它可以用于输入的任何单词)？

谢谢。对于冗长的帖子，我们深表歉意。

Answer 1

您正在使用目标字母表进行检查，然后使用错误的索引和源字母表进行修改。

这个:

    if (altAlpha[i] == sentence[j])
    {
        sentence[i] = regAlpha[i];
    }

应该是:

    if (regAlpha[i] == sentence[j])
    {
        sentence[j] = altAlpha[i]; 
        break; 
    }

中断是必要的，以避免多次加密某些字符。

---

您还需要更改循环的顺序以避免多次加密某些字符。所以这个:

for (int i = 0; i < lenAlpha; i++)
{
    for (int j = 0; j < lenSent; j++)

变成:

for (int j = 0; j < lenSent; j++)
{
    for (int i = 0; i < lenAlpha; i++)

---

将它们拼接在一起，您的 for 循环应该如下所示:

for (int j = 0; j < lenSent; j++)
{
    for (int i = 0; i < lenAlpha; i++)
    {
        if (regAlpha[i] == sentence[j])
        {
            sentence[j] = altAlpha[i]; 
            break;
        }
    }
}