C++簡單的輸入處理（2個由空格分隔的字符數組）

Question

我的問題是，我試圖輸入未知數量的對： - 一對中的第一個元素是一個詞（我不能使用字符串，只有字符與char * []） - 那麼有一個空間 -the第二字（字符串也不允許） 再有就是新行符號

在不使用字符串，哪能最有效地輸入這兩個話？什麼放在while(!cin.eof())循環？

Answer 1

從這裏開始。如果我是你，我會閱讀關於IO的所有常見問題。這似乎是一個簡單的作業任務，可以通過幾種方式完成，但我認爲最好是給你指導而不是爲你做功課。 http://www.parashift.com/c++-faq/input-output.html http://www.parashift.com/c++-faq/istream-and-eof.html

Answer 2

看看這個作品你...

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

/* Read a string, split it into two sub-strings with space as the delimiter 
    return true if split succeeded otherwise return false 

    sample execution: 
     input: abc def 
     output: *firstWord = abc *secondWord = def 
     return value: true 

     input: abc def ghi 
     output: *firstWord = abc, *secondWord = def ghi 
     return value: true 

     input: abc 
     output: *firstWord = undefined, *secondWord = undefined 
     return value: false 
*/ 

bool readLineAndSplit(char* input, char** firstWord, char** secondWord) 
{ 
    if (*firstWord) 
     delete [] *firstWord; 
    if (*secondWord) 
     delete [] *secondWord; 

    int len = strlen(input); 

    if (!len) 
     return false; 

    // pointer to last character in the input 
    char* end = input + len - 1; // last character in input 

    // read first word, scan until a space is encountered 
    char* word = input; 
    while(*word != ' ' && word < end) 
    { 
     word++; 
    } 
    // error: no spaces 
    if (word == end) 
    { 
     cout << input << " isn't valid! No spaces found!" <<endl; 
     return false; 
    } 
    else 
    { 
     *firstWord = new char[(word-input) + 1]; // +1 for '\0' 
     *secondWord = new char[(end-word) + 1]; // +1 for '\0' 
     strncpy(*firstWord, input, word-input); 
     strncpy(*secondWord, word+1, end-word); 
     (*firstWord)[word-input] = '\0'; 
     (*secondWord)[end-word] = '\0'; 
    } 

    return true; 
} 

int main() 
{ 
    char input[1024]; 
    while (true) 
    { 
     cin.getline(input, 1024); 
     if (strlen(input) == 0) 
      break; 
     else 
     { 
      char* firstWord = NULL, *secondWord = NULL; 
      if (readLineAndSplit(input, &firstWord, &secondWord)) 
      { 
       cout << "First Word = " << firstWord << " Second Word = " << secondWord << endl; 
      } 
      else 
      { 
       cout << "Error: " << input << " can't be split!" << endl; 
       break; 
      } 
     } 
    } 
    return 0; 
}