C ++一次打印一个单词，计算字符数，平均字符数

Question

如何从每行的字符串中打印一个单词，并在其旁边显示字符数以及字符的平均值？我想使用字符串成员函数将对象转换为 c 字符串。 countWords 函数接受 c 字符串并返回一个 int。该函数假设读取每个单词及其长度，包括字符的平均值。我已经完成了字符串中有多少单词，除了我不知道如何继续其余的。

例如：超级大炮男孩

超级5

伟大的 5

大炮 6

男孩 4

平均字符数：5

这是我目前的程序：

#include <iostream>
#include <string>
#include <cstring>

using namespace std;

int countWords(char *sentence);

int main()
{
    const int size=80;
    char word[size];
    double average=0;
    cout<<"Enter words less than " <<size-1<<" characters."<<endl;
    cin.getline(word, size);
    cout <<"There are "<<countWords(word)<<" words in the sentence."<<endl;

    return 0;
}

int countWords(char *sentence)
{
    int words= 1;
    while(*sentence != '\0')
    {
        if(*sentence == ' ')
            words++;
        sentence++;
    }
    return words;
}

Answer 1

除非这是禁止这样做的家庭作业，否则您几乎肯定希望使用std::string 以及与std::string 一起使用的std::getline 版本，而不是char 的原始缓冲区：

std::string s;
std::getline(std::cin, s);

然后您可以通过将行填充到std::istringstream 中来计算单词，然后从那里读取单词：

std::istringstream buffer(s);
auto word_count = std::count(std::istream_iterator<std::string>(s), 
                             std::istream_iterator<std::string());

要随时打印出单词及其长度，您可以（例如）改用std::for_each：

int count = 0;
std::for_each(std::istream_iterator<std::string>(s),
              std::istream_iterator<std::string>(),
              [&](std::string const &s) { 
                  std::cout << s << " " << s.size();
                  ++count;});

Answer 2

这应该与您的要求相差不远 - 我只对您当前的代码进行了少量修改。

限制：

• 你最好用

  string line;
  getline(cin, line);
  

  读取行以能够接受任何大小的行

• 我目前的代码假设

  • 行首或行尾无空格
  • 两个单词之间有一个空格

  应该改进它以应对额外的空间，但我把它留给你作为练习:-)

代码：

#include <iostream>
#include <string>
#include <cstring>

using namespace std;

int countWords(char *sentence, double& average);

int main()
{
const int size=80;
char word[size];
double average=0;
cout<<"Enter words less than " <<size-1<<" characters."<<endl;
cin.getline(word, size);
cout <<"There are "<<countWords(word, average)<<" words in the sentence."<<endl;
cout << "Average of the sentence " << average << endl;
return 0;
}

int countWords(char *sentence, double& average)
{
int words= 1;
int wordlen;
char *word = NULL;
while(*sentence != '\0')
{
    if(*sentence == ' ') {
        words++;
        wordlen = sentence - word;
        average += wordlen;
        *sentence = '\0';
        cout << word << " " << wordlen<< endl;  
        word = NULL;
    }
    else if (word == NULL) word = sentence;
    sentence++;
}
wordlen = sentence - word;
average += wordlen;
cout << word << " " << wordlen<< endl;  
average /= words;
return words;

}

输入：super great cannon boys

输出是：

Enter words less than 79 characters.
super great cannon boys
super 5
great 5
cannon 6
boys 4
There are 4 words in the sentence.
Average of the sentence 5

Answer 3

您可以在这里激发灵感。基本上使用std::getline 从std::cin 读取到std::string。

#include <iostream>
#include <string>
#include <cctype>

inline void printWordInfo(std::string& word) {

    std::cout << "WORD: " << word << ", CHARS: " << word.length() << std::endl;

}

void printInfo(std::string& line) {

    bool space = false;
    int words = 0;
    int chars = 0;
    std::string current_word;


    for(std::string::iterator it = line.begin(); it != line.end(); ++it) {

        char c = *it;

        if (isspace(c)) {

            if (!space) {

                printWordInfo(current_word);
                current_word.clear();
                space = true;
                words++;

            }
        }
        else {

            space = false;
            chars++;
            current_word.push_back(c);

        }

    }

    if (current_word.length()) {

        words++;
        printWordInfo(current_word);

    }

    if (words) {

        std::cout << "AVERAGE:" << (double)chars/words << std::endl;

    }

}

int main(int argc, char * argv[]) {

    std::string line;

    std::getline(std::cin, line);

    printInfo(line);

    return 0;

}

Answer 4

按照你已经拥有的路线：

您可以定义一个 countCharacters 函数，例如您的 countWords：

int countCharacters(char *sentence)
{
  int i;
  char word[size];
  for(i = 0; sentence[i] != ' '; i++) //iterate via index
  {
    word[i] = sentence[i];   //save the current word
    i++;
  }
  cout <<word<< <<i<<endl; //print word & number of chars
  return i;
}

您可以在 countWords 函数中调用它

int countWords(char *sentence)
{
  int words = 1;
  for(int i; sentence[i] != '\0';) //again this for loop, but without
                                   //increasing i automatically
  {
     if(sentence[i] == ' ') {
       i += countCharacters(sentence[++i]);  //move i one forward to skip
                                             // the space, and then move 
                                             // i with the amount of 
                                             // characters we just counted
       words++;                              
     }
     else i++;
  }
  return words;
}