c - 如何用 C 语言编写代码来检查字符串中的重复单词并计算它们出现的次数？

Question

我现在正在为我的类(class)编写一段代码，用于分析手动插入的文本。我应该找到非空格字符的总数和单词总数。另外，我应该找到字符串中任何重复的单词，然后显示它们的重复次数。我陷入了寻找重复单词并显示重复次数的困境。另外，我对 C 的了解有限，我所知道的主题包括指针、字符串、文件和函数、循环、if 条件等......下面是我到目前为止的代码:

#include <stdio.h>

int num, numi, text, length, length1, word;
numi = 0;
word = 1;

int main()
{
    char text[] = "Dennis        MacAlistair Ritchie (September 9, 1941 - October 12, 2011) was an American computer scientist. He created the C programming language and, with long-time colleague Ken Thompson, the Unix operating system and B programming language. Dennis Ritchie was born in Bronxville, New York. His father was Alistair E. Ritchie, a long-time Bell Labs scientist and co-author of The Design of Switching Circuits on switching circuit theory. As a child, Dennis moved with his family to Summit, New Jersey, where he graduated from Summit High School. He graduated from Harvard University with degrees in physics and applied mathematics.";
    printf("Welcome to UNM Text Editor. Your original text is:\n\n");
    printf("%s", text);
    length = strlen(text);
    for (numi=0; numi<=length; numi++)
    {
        if (text[numi] == ' ')
        {
            length1++;
            if (text[numi + 1] != ' ')
            {
                word++;
            }
        }
    }
    printf("\n\nThe total number of characters (without spaces) is: %d", length-length1);
    printf("\nThe total number of words is: %d", word);
}

Answer 1

根据我在评论中读到的内容，您已经解决了前两点，因此我将主要关注重复。

为此，您可以使用 Trie 数据结构，请查看下面的链接。

https://www.geeksforgeeks.org/trie-display-content/

它是用 C++ 编写的，但真正使用 C++ 中的东西并不多，因此可以轻松地将其重写为 C。您只需在 GeeksForGeeks 代码中添加几行即可使其工作。因为这是你的类(class)作业，也许你不应该只使用整个代码，而应该编写自己的代码，但我想向你展示总体想法，

1. 将可变数量的“string”添加到结构中:

   
   struct TrieNode
   {
       struct TrieNode* children[alpha_size];
       bool isLeaf;
       int occurrence; // <-- I ADDED IT HERE
   }
   

2. 在insert_node_function末尾添加:

   
   ...
   pCrawl->isLeaf = true;
   pCrawl->occurrence++; // <-- I ADDED IT HERE
   ...
   

3. 仅当出现次数大于1时显示

   <p></p>
   
   <p>void display(struct TrieNode* root, char str[], int level)
   {
       // If node is leaf node, it indicates end 
       // of string, so a null character is added 
       // and string is displayed 
       if (isLeafNode(root) && root->occurrence > 1)  // <-- I ADDED IT HERE
       {
           str[level] = '\0';
           cout << str << " " << root->occurrence << endl;  // <-- I ADDED IT HERE
       }
       ...
   </p>

剩下的一件事是如何从“文本”(示例中的字 rune 本)中读取单个单词。为了方便起见，您可以删除所有重复的空格并再次浏览文本。然后，您可以复制将空格作为分隔符的单词(例如通过使用 strncat)并插入到 trie 中。

要了解 trie 的工作原理，请尝试用 google 搜索它。应该有很多关于它的信息。