Question

此函数用于从char数组中删除所有特殊字符，数字和空格。

// Michael E. Torres II
// Vigenere Cipher
// February 4, 2018

// C++ code to implement Vigenere Cipher
#include <iostream>
#include <string>
#include <iomanip>
#include <fstream>
#include <algorithm>
#include <cctype>
#include <iterator>
#include <sstream>
#include <functional>
using namespace std;

// This function generates the key in
// a cyclic manner until it's length isi'nt
// equal to the length of original text
string generateKey(string str, string key)
{
    int x = str.size();

    for (int i = 0; ; i++)
    {
        if (x == i)
            i = 0;
        if (key.size() == str.size())
            break;
        key.push_back(key[i]);
    }
    return key;
}

// This function returns the encrypted text
// generated with the help of the key
string cipherText(string str, string key)
{
    string cipher_text;

    for (int i = 0; i < str.size(); i++)
    {
        // converting in range 0-25
        int x = (str[i] + key[i]) % 26;

        // convert into alphabets(ASCII)
        x += 'A';

        cipher_text.push_back(x);
    }
    return cipher_text;
}

// This function decrypts the encrypted text
// and returns the original text
string originalText(string cipher_text, string key)
{
    string orig_text;

    for (int i = 0; i < cipher_text.size(); i++)
    {
        // converting in range 0-25
        int x = (cipher_text[i] - key[i] + 26) % 26;

        // convert into alphabets(ASCII)
        x += 'A';
        orig_text.push_back(x);
        transform(orig_text.begin(), orig_text.end(), orig_text.begin(), ::tolower);
    }
    return orig_text;
}

string removeNonAlpha(char *str)
{
    unsigned long i = 0;
    unsigned long j = 0;
    char c;

    while ((c = str[i++]) != '\0')
    {
        if (isalpha(c))  // this is where the breakpoint is automatically placed
        {
            str[j++] = c;
        }
    }
    str[j] = '\0';
    return str;

}

// Driver program to test the above function
int main(int argc, char *argv[])
{
    string keyword = "bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb";
    stringstream ss;
    char a[] = "“I think and think for months and years. Ninety-nine times, the conclusion is false. The hundredth time I am right.” – Albert Einstein “Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world, stimulating progress, giving birth to evolution.” – Albert Einstein";
    int i = 0;

  string str = removeNonAlpha(a);

    str.append(512 - str.length(), 'X');

    transform(str.begin(), str.end(), str.begin(), ::toupper);


    transform(keyword.begin(), keyword.end(), keyword.begin(), ::toupper);


    string key = generateKey(str, keyword);
    string cipher_text = cipherText(str, key);

    transform(cipher_text.begin(), cipher_text.end(), cipher_text.begin(), ::tolower);
    transform(key.begin(), key.end(), key.begin(), ::tolower);

    string orig = originalText(cipher_text, key);

    cout << "Original/Decrypted Text : " << "\n";

    for (int i = 0; i < orig.size(); i += 81)
        orig.insert(i, "\n");
    cout << orig;

    cout << "\n\n" << "Ciphertext : " << "\n";

    for (int i = 0; i < cipher_text.size(); i += 81)
        cipher_text.insert(i, "\n");

    cout << cipher_text;

    cout << "\n\nPress ENTER key to Continue\n";
    getchar();

    return 0;
}

只要没有特殊字符[。，％$ @！^]，char数组就可以正常使用while循环。只要char数组中有任何特殊字符，它就会给我调试断言：

＆＃34;程序：... \ Projects \ ConsoleApplication17 \ Debug \ ConsoleApplication17.exe 文件：minkernel \ crts \ ucrt \ src \ appcrt \ convert \ isctype.cpp 行：42

表达式：c＆gt; = -1＆amp;＆amp; c＆lt; = 255

...

程序＆＃39; [11048] ConsoleApplication17.exe＆＃39;退出了代码3（0x3）。＆＃34;

如果我在repl.it或cpp.sh上运行它，我不会遇到任何问题。我感谢任何帮助。谢谢。

根本没有完成。它需要清理很多，但我只是试图按原样进行测试。

Answer 1

见https://msdn.microsoft.com/en-us/library/xt82b8z8.aspx isalpha需要一个介于0和0xFF之间的数字：

如果c不是EOF或，则isalpha和_isalpha_l的行为是不确定的在0到0xFF的范围内，包括0和0xFF。当一个调试CRT库 used和c不是这些值中的一个，函数引发了断言。

在传递给isalpha之前，你需要将char转换为unsigned char。

使用Microsoft VS在C ++中编写程序，但我在这里得到一个调试断言消息。它运行在cpp.sh和repl.it上，但不在VS上。我该怎么办？

1 个答案: