我第一次尝试创建一个词表，

Question

我试图创建一个包含所有字母组合（大写和小写）和一些符号的词汇表。基本上大部分是ASCII表。

我只是想知道文本文件将占用多少内存。我想我会用一些其他功能来删除不必要的单词。但是现在我祈祷我的1 TB硬盘不会爆炸。 我不知道这个方法是否是正确的方法，使用带有下标数组的嵌套for循环，也许我应该使用链表来获得更好的性能。与此同时，我可以创建删除字符多于某些字符的行的函数。

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define PATH "wordlist.txt"
#define SIZE 68



void Write(char * word[], FILE * f, int N)
{
for(int i = 0; i <= N; i++)
  {
  fprintf(f,"%s", word[i]);
  }
  fprintf(f,"\n");
}




void thirteen_Digits(char * word[],char * letters[] , FILE * f)
{
  for(int i = 0; i < SIZE; i++)
  {
    word[0] = letters[i];
    for(int j = 0; j < SIZE ;j++)
      {
        word[1] = letters[j];
        for(int k = 0; k < SIZE; k++)
        {
          word[2] = letters[k];
          for(int l = 0; l < SIZE;l++)
          {
            word[3] = letters[l];
            for(int m = 0; m< SIZE; m++)
            {
              word[4] = letters[m];
              for(int n = 0; n < SIZE; n++)
              {
                word[5] = letters[n];
                for(int o = 0; o < SIZE; o++)
                {
                  word[6] = letters[o];
                  for(int p = 0; p < SIZE; p++)
                  {
                    word[7] = letters[p];
                    for(int q = 0; q < SIZE; q++)
                    {
                      word[8] = letters[q];
                      for(int r = 0; r < SIZE; r++)
                      {
                        word[9] = letters[r];
                        for(int s = 0; s < SIZE;s++)
                        {
                          word[10] = letters[s];
                          for(int t = 0; t < SIZE; t++)
                          {
                            word[11] = letters[t];
                            for(int u = 0; u < SIZE; u++)
                            {
                              word[12] = letters[u];
                              Write(word, f, 12);
                            }
                          }
                        }
                      }
                    }
                  }
                }
              }
            }
          }
        }
      }
    }

fclose(f);
}

void twelve_Digits(char * word[],char * letters[] , FILE * f)
{
for(int i = 0; i < SIZE; i++)
{
  word[0] = letters[i];
  for(int j = 0; j < SIZE ;j++)
    {
      word[1] = letters[j];
      for(int k = 0; k < SIZE; k++)
      {
        word[2] = letters[k];
        for(int l = 0; l < SIZE;l++)
        {
          word[3] = letters[l];
          for(int m = 0; m< SIZE; m++)
          {
            word[4] = letters[m];
            for(int n = 0; n < SIZE; n++)
            {
              word[5] = letters[n];
              for(int o = 0; o < SIZE; o++)
              {
                word[6] = letters[o];
                for(int p = 0; p < SIZE; p++)
                {
                  word[7] = letters[p];
                  for(int q = 0; q < SIZE; q++)
                  {
                    word[8] = letters[q];
                    for(int r = 0; r < SIZE; r++)
                    {
                      word[9] = letters[r];
                      for(int s = 0; s < SIZE;s++)
                      {
                        word[10] = letters[s];
                        for(int t = 0; t < SIZE; t++)
                        {
                          word[11] = letters[t];
                          Write(word, f,11);
                        }
                      }
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

void eleven_Digits(char * word[],char * letters[] , FILE * f)
{
for(int i = 0; i < SIZE; i++)
{
  word[0] = letters[i];
  for(int j = 0; j < SIZE ;j++)
    {
      word[1] = letters[j];
      for(int k = 0; k < SIZE; k++)
      {
        word[2] = letters[k];
        for(int l = 0; l < SIZE;l++)
        {
          word[3] = letters[l];
          for(int m = 0; m< SIZE; m++)
          {
            word[4] = letters[m];
            for(int n = 0; n < SIZE; n++)
            {
              word[5] = letters[n];
              for(int o = 0; o < SIZE; o++)
              {
                word[6] = letters[o];
                for(int p = 0; p < SIZE; p++)
                {
                  word[7] = letters[p];
                  for(int q = 0; q < SIZE; q++)
                  {
                    word[8] = letters[q];
                    for(int r = 0; r < SIZE; r++)
                    {
                      word[9] = letters[r];
                      for(int s = 0; s < SIZE;s++)
                      {
                        word[10] = letters[s];
                        Write(word, f,10);
                      }
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

void ten_Digits(char * word[],char * letters[] , FILE * f)
{
for(int i = 0; i < SIZE; i++)
{
  word[0] = letters[i];
  for(int j = 0; j < SIZE ;j++)
    {
      word[1] = letters[j];
      for(int k = 0; k < SIZE; k++)
      {
        word[2] = letters[k];
        for(int l = 0; l < SIZE;l++)
        {
          word[3] = letters[l];
          for(int m = 0; m< SIZE; m++)
          {
            word[4] = letters[m];
            for(int n = 0; n < SIZE; n++)
            {
              word[5] = letters[n];
              for(int o = 0; o < SIZE; o++)
              {
                word[6] = letters[o];
                for(int p = 0; p < SIZE; p++)
                {
                  word[7] = letters[p];
                  for(int q = 0; q < SIZE; q++)
                  {
                    word[8] = letters[q];
                    for(int r = 0; r < SIZE; r++)
                    {
                      word[9] = letters[r];
                      Write(word, f,9);
                    }
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

void nine_Digits(char * word[], char * letters[] ,FILE * f)
{
for(int i = 0; i < SIZE; i++)
{
  word[0] = letters[i];
  for(int j = 0; j < SIZE ;j++)
    {
      word[1] = letters[j];
      for(int k = 0; k < SIZE; k++)
      {
        word[2] = letters[k];
        for(int l = 0; l < SIZE;l++)
        {
          word[3] = letters[l];
          for(int m = 0; m< SIZE; m++)
          {
            word[4] = letters[m];
            for(int n = 0; n < SIZE; n++)
            {
              word[5] = letters[n];
              for(int o = 0; o < SIZE; o++)
              {
                word[6] = letters[o];
                for(int p = 0; p < SIZE; p++)
                {
                  word[7] = letters[p];
                  for(int q = 0; q < SIZE; q++)
                  {
                    word[8] = letters[q];
                    Write(word, f,  8);
                  }
                }
              }
            }
          }
        }
      }
    }
  }
}

void eight_Digits(char * word[],char * letters[] , FILE * f)
{
for(int i = 0; i < SIZE; i++)
{
  word[0] = letters[i];
  for(int j = 0; j < SIZE ;j++)
    {
      word[1] = letters[j];
      for(int k = 0; k < SIZE; k++)
      {
        word[2] = letters[k];
        for(int l = 0; l < SIZE;l++)
        {
          word[3] = letters[l];
          for(int m = 0; m< SIZE; m++)
          {
            word[4] = letters[m];
            for(int n = 0; n < SIZE; n++)
            {
              word[5] = letters[n];
              for(int o = 0; o < SIZE; o++)
              {
                word[6] = letters[o];
                for(int p = 0; p < SIZE; p++)
                {
                  word[7] = letters[p];
                  Write(word, f, 7);
                }
              }
            }
          }
        }
      }
    }
  }
}

void seven_Digits(char * word[], char * letters[] ,FILE * f)
{
for(int i = 0; i < SIZE; i++)
{
  word[0] = letters[i];
  for(int j = 0; j < SIZE ;j++)
    {
      word[1] = letters[j];
      for(int k = 0; k < SIZE; k++)
      {
        word[2] = letters[k];
        for(int l = 0; l < SIZE;l++)
        {
          word[3] = letters[l];
          for(int m = 0; m< SIZE; m++)
          {
            word[4] = letters[m];
            for(int n = 0; n < SIZE; n++)
            {
              word[5] = letters[n];
              for(int o = 0; o < SIZE; o++)
              {
                word[6] = letters[o];
                  Write(word, f, 6);
              }
            }
          }
        }
      }
    }
  }
}

void six_Digits(char * word[],char * letters[] , FILE * f)
{
for(int i = 0; i < SIZE; i++)
{
  word[0] = letters[i];
  for(int j = 0; j < SIZE ;j++)
    {
      word[1] = letters[j];
      for(int k = 0; k < SIZE; k++)
      {
        word[2] = letters[k];
        for(int l = 0; l < SIZE;l++)
        {
          word[3] = letters[l];
          for(int m = 0; m< SIZE; m++)
          {
            word[4] = letters[m];
            for(int n = 0; n < SIZE; n++)
            {
              word[5] = letters[n];
              Write(word, f, 5);
            }
          }
        }
      }
    }
  }
}
void five_Digits(char * word[],char * letters[] , FILE * f)
{
for(int i = 0; i < SIZE; i++)
{
  word[0] = letters[i];
  for(int j = 0; j < SIZE ;j++)
    {
      word[1] = letters[j];
      for(int k = 0; k < SIZE; k++)
      {
        word[2] = letters[k];
        for(int l = 0; l < SIZE;l++)
        {
          word[3] = letters[l];
          for(int m = 0; m< SIZE; m++)
          {
            word[4] = letters[m];
            Write(word, f, 4);
          }
        }
      }
    }
  }
}

void four_Digits(char * word[], char * letters[] ,FILE * f)
{
for(int i = 0; i < SIZE; i++)
{
  word[0] = letters[i];
  for(int j = 0; j < SIZE ;j++)
    {
      word[1] = letters[j];
      for(int k = 0; k < SIZE; k++)
      {
        word[2] = letters[k];
        for(int l = 0; l < SIZE;l++)
        {
          word[3] = letters[l];
          Write(word, f, 3);
        }
      }
    }
  }
}


int main()
{
  FILE *f;

  if(!(f=fopen(PATH, "a")))
  {
    perror("Errore");
    exit(-1);
  }


  char * letters[SIZE] = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z",
                          "a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z",
                          ".","_","1","2","3","4","5","6","7","8","9","0","!","@","$","§"};

  char * word13[] = {"A","A","A","A","A","A","A","A","A","A","A","A","A"};
  char * word12[] = {"A","A","A","A","A","A","A","A","A","A","A","A"};
  char * word11[] = {"A","A","A","A","A","A","A","A","A","A","A"};
  char * word10[] = {"A","A","A","A","A","A","A","A","A","A"};
  char * word9[] = {"A","A","A","A","A","A","A","A","A"};
  char * word8[] = {"A","A","A","A","A","A","A","A"};
  char * word7[] = {"A","A","A","A","A","A","A"};
  char * word6[] = {"A","A","A","A","A","A"};
  char * word5[] = {"A","A","A","A","A"};
  char * word4[] = {"A","A","A","A"};

 four_Digits(word4,letters, f);
 five_Digits(word5,letters, f);
 six_Digits(word6,letters, f);
 seven_Digits(word7,letters, f);
 eight_Digits(word8,letters, f);
 nine_Digits(word9,letters, f);
 ten_Digits(word10, letters,f);
 eleven_Digits(word11,letters, f);
 twelve_Digits(word12, letters,f);
 thirteen_Digits(word13,letters, f);

exit(EXIT_SUCCESS);
}

我将非常感谢让alghorithm更快的任何帮助。

Answer 1

这个程序不会在你的生命周期内完成 - 它会在很久之前填满你的硬盘。

有68个 ¹³ = 6×10 ²³ 可能的组合，其中包括从68个字符集中选择的13个字符。每个14字节（13个字符+一个换行符），将它们全部存储在一个文件中将需要大约9.3×10 ²⁴ 字节，或 9.3万亿太字节。这比地球上存在的数据存储量大几个数量级。

你需要重新考虑你在这里要做的事情。这显然不起作用。

从实现的角度来看，有一种比使用嵌套循环更简单的方法：

void permute(int length, int maximum_digit)
{
    int *digits = calloc(length, sizeof(int));
    do {
        print_digits(digits, length);
    } while (increment(digits, length, maximum_digit));
    free(digits);
}

此函数创建一个可变位数的数组（由length设置），并在每一步“递增”该数组，直到达到最大值（maximum_digit）。

我们可以通过逐步遍历数组来实现增量;对于每个数字，我们将其递增并在其低于其最大值时停止，或者将其归零并以其他方式继续：

int increment(int *digits, int length, int maximum_digit)
{
    for (int i = 0; i < length; i++) {
        if (digits[i] + 1 == maximum_digit) {
            digits[i] = 0;
        } else {
            digits[i]++;
            return 1;
        }
    }
    return 0;
}

print_digits()的实现留给读者。