将单词读入指向结构的动态分配数组

Question

我正在尝试获取用户输入的字符串，然后将其清理一下并将逐字存储在动态分配的数组中。该数组指向一个结构。我试图将数组存储在 "English" 结构变量中。

这是我想出的，但是当我运行代码时，我的数组测试 cout 没有输出，所以我觉得这些词没有被复制到数组中。

//This program will take in a English sentence from the user where it will then store the string in an dynamically allocated array
//where it will be run through a functions which will convert the English sentence to pig Latin. The
//final sentence will be displayed to the screen for the user to see.

#include <iostream>
#include <cstring>
#include <string>
using namespace std;

struct Word{
    string english;
    string piglatin;
};

Word * sentenceSetup(string, int &);




int main()
{
    int Size=1;//default how many words in the sentence.

    string userSent;

    //ask the user for a sentence they want to convert
    cout<<"Hello, please enter a string to convert to PigLatin: "<<endl;
    getline(cin, userSent);


    Word * arr = sentenceSetup(userSent,Size);
    for (int i=0; i<Size;i++)
    {
        cout<< arr[i].english<<endl;
    }

    return 0;

}

//**************************************************************
//sentenceSetup Definition: In this function we will be asking *
//the user to enter in a string which then will be counted     *
//for how many words it has and creating an array of structs   *
//big enough to hold that string. The array will then be       *
//returned to the calling function. NOTE: This function should *
//remove all capitalization and special characters except for  *
//the end period, exclamation mark, or question mark.          *
//**************************************************************

Word * sentenceSetup(string userSent, int &size)
{

    char nextCharacter;

    //check the input for any unwanted special characters not listed in the     function def.
    for( int i=0; i<int(userSent.size()); i++)
    {
        nextCharacter = userSent.at(i);
        if(ispunct(userSent[i]))
        {

            userSent.erase(i--, 1);
        }
    }

    //change the whole sentence to lower case
    for (int i=0; i<int(userSent.size()); i++)
    {
        userSent[i]=tolower(userSent[i]);
    }

    //Check each character in the string to see if it is a space. If the loop
    //notices a space then a space equals a word in the string.
    for (int i =0; i<int(userSent.size());i++)
    {

        nextCharacter = userSent.at(i); //Reads the character
        if(isspace(userSent[i]))
        {

            size++;

        }


    }

    //test to see if num count works
    cout<<"There is "<<size << " words in the sentence."<<endl;
    //test to see if special characters removed
    //cout<<userSent<<endl;


    //allocate an array to store the words in for the struct Word
    Word *temp= new Word[size];
    int count =0;
    string word;
    for(count=0;count<size;count++)
    {
        if(isspace(userSent[count]))
        {

            word =userSent.substr(0,count);
            temp[count].english=word;
            userSent.erase(0,count);
        }


    }


    //test
    for(count =0; count<size;count++)
    {
        cout<<temp[count].english;
    }
    return temp;
}

Answer 1

问题在于您如何尝试将数据写入动态分配的 Word* 临时变量以及您为此使用的 for 循环。以上代码需要修改如下

我正在创建一个 main 字符串数组，该数组将由函数

返回

//allocate an array to store the words in for the struct Word
    Word *main= new Word[size];
    int count =0;
    string word;
    //Variable to keep track of start of each word
    int start_count =0;
    //Create a temp pointer to iterate through the memory allocated for each word
    Word *temp = main;
    //Variable to keep track of length of each word
    int bytes_to_cpy =0;

for循环应该循环到句子的长度，而不仅仅是单词的数量

 for(count=0;count<=userSent.length();count++){

        if(isspace(userSent[count]))
        {
        //Copy the required bytes as a substring
            word =userSent.substr(start_count,bytes_to_cpy);
            //Copy the word to the main array
            temp->english=word;
            //Increment the pointer;
            temp++;
            //Ignore the white space for the next word
            start_count=count+1;
            //Reset the length of the word
            bytes_to_cpy=0;
        }
    //Count the length of the word
    bytes_to_cpy++;
    }

    //Add the last word to the array
    word =userSent.substr(start_count,userSent.length()-start_count);


    temp->english = word;
    temp = main;

    //test

    for(count =0; count<size;count++)
    {
        cout<<temp->english<<endl;
    temp++;
    }
    return main;

除此之外，您还需要处理多个空格，在我们计算字数的函数中用户输入字符串开头和结尾的空格。您当前的实施不考虑这些。

将单词读入指向结构的动态分配数组

Reading in words to a dynamically allocated array pointing to a struct

c++

arrays

struct

pointers

dynamic-arrays