當我由於某種原因，在文件中讀取它通過它改變了文件中的位置自

Question

當我爲退出讀取文件中的，由於某種原因，跳過完全相同的量num_rooms

我知道有一個錯誤後完成的地方調用該函數read_rooms和進入而下一次迭代（input.good（））

const int MAX_ROOMS = 50; 
const int MAX_EXITS = MAX_ROOMS * 4  
std::ifstream input; 
int read_world(std::ifstream &input, std::string rooms[MAX_ROOMS], int &num_rooms, bool exits[MAX_EXITS], 
       int &num_exits); 
int read_rooms(std::ifstream &input, std::string rooms[MAX_ROOMS], int &num_rooms); 
int read_exits(std::ifstream &input, bool exits[], int &num_exits); 

int main() { 
    char fileName[26]; 
    std::cout<<"filename::"; 
    std::cin.getline(fileName, 26); 
    input.open(fileName, std::ios::in); 
    std::string rooms[MAX_ROOMS]; 
    int num_rooms; 
    bool exits[MAX_EXITS]; 
    int num_exits; 
    read_world(input,rooms,num_rooms,exits,num_exits); 
    input.close(); 
    return 0; 
}; 
int read_world(std::ifstream &input, std::string rooms[MAX_ROOMS], int &num_rooms, bool exits[MAX_EXITS], 
       int &num_exits) { 
     std::string fnCaller; 
     while (!input.eof()) { 
      getline(input, fnCaller, ' ');// to check which function to call 
      if (fnCaller == "rooms") { 
       std::string temp; 
       getline(input, temp); 
       num_rooms = atoi(temp.c_str()); 
       read_rooms(input, rooms, num_rooms); 
      } 
      getline(input, fnCaller, ' '); 
      if (fnCaller == "exits") { 
       std::string temp; 
       getline(input, temp, ' '); 
       num_exits = atoi(temp.c_str()); 
       read_exits(input, exits, num_exits); 
      } 
     } 
    }; 

    int read_rooms(std::ifstream &input, std::string rooms[MAX_ROOMS], int &num_rooms) { 
     for (int i = 0; i < num_rooms; i++) {//get the info 
      std::string str; 
      getline(input, str, '\n'); 
      rooms[i] = str; 
     } 
     return 0; 
    }; 

int read_exits(std::ifstream &input, bool exits[], int &num_exits) { 
     for (int i = 0; i < num_exits; i++) {//get the info 
      std::string str; 
      getline(input, str); 
      std::cout<<str<<std::endl; 
      if (str == "locked") { 
      exits[i] = true; 
      } else if (str == "unlocked") { 
       exits[i] = false; 
      } 
     } 
     return 0; 
    }; 

這是我的文件內容

rooms 7 

front of the house 

living room 

guest bedroom 

closet 

hallway 

master bedroom 

garden 

exits 6 

locked 

locked 

unlocked 

unlocked 

locked 

locked 

Answer 1

有兩件事我注意到：

• 一個問題是，你調用getline（input，fnCaller，''）;第二次，所以如果它不等於第一次讀取的空間，那麼數字值會在第二次讀取時讀入fnCaller。刪除第二個getline（input，fnCaller，''）;
• 另一個問題是，當您讀取用空格分隔的出口大小，但在下一次讀取fnCaller之前沒有空格，因此讀入temp的出口數爲6 \ nlocked \ nlocked \ nunlocked \ nunlocked \ nlocked \ nlocked，因此您需要像讀取房間數一樣讀取該數字：getline（input，temp）;

這與這兩個變化：

#include <fstream> 
#include <iostream> 

const int MAX_ROOMS = 50; 
const int MAX_EXITS = MAX_ROOMS * 4; 
std::ifstream input; 
int read_world(std::ifstream &input, std::string rooms[MAX_ROOMS], int &num_rooms, 
       bool exits[MAX_EXITS], int &num_exits); 
int read_rooms(std::ifstream &input, std::string rooms[MAX_ROOMS], int &num_rooms); 
int read_exits(std::ifstream &input, bool exits[], int &num_exits); 

int main() { 
    std::string fileName; 
    std::cout<<"filename::"; 
    std::getline(std::cin,fileName); 
    input.open(fileName, std::ios::in); 
    if(input) { 
     std::string rooms[MAX_ROOMS]; 
     int num_rooms; 
     bool exits[MAX_EXITS]; 
     int num_exits; 
     read_world(input,rooms,num_rooms,exits,num_exits); 
     input.close(); 
    } else { 
     std::cout<<"Error: couldn't read from "<<fileName<<std::endl; 
    } 
    return 0; 
}; 

int read_world(std::ifstream &input, std::string rooms[MAX_ROOMS], int &num_rooms, 
       bool exits[MAX_EXITS], int &num_exits) { 
    std::string fnCaller; 
    while (std::getline(input, fnCaller, ' ')) { // to check which function to call 
     std::cout<<"function::"<<fnCaller<<"\n"; 
     if (fnCaller == "rooms") { 
      std::string temp; 
      getline(input, temp); 
      std::cout<<"num_rooms::"<<temp<<"\n"; 
      num_rooms = atoi(temp.c_str()); 
      read_rooms(input, rooms, num_rooms); 
     } 
     if (fnCaller == "exits") { 
      std::string temp; 
      std::getline(input, temp); 
      std::cout<<"num_exits::"<<temp<<"\n"; 
      num_exits = atoi(temp.c_str()); 
      read_exits(input, exits, num_exits); 
     } 
    } 
}; 

int read_rooms(std::ifstream &input, std::string rooms[MAX_ROOMS], int &num_rooms) { 
    for (int i = 0; i < num_rooms; i++) {//get the info 
     std::string str; 
     std::getline(input, str); 
     std::cout<<"room["<<i<<"]::"<<str<<"\n"; 
     rooms[i] = str; 
    } 
    return 0; 
}; 

int read_exits(std::ifstream &input, bool exits[], int &num_exits) { 
    for (int i = 0; i < num_exits; i++) {//get the info 
     std::string str; 
     std::getline(input, str); 
     std::cout<<"exit["<<i<<"]::"<<str<<"\n"; 
     if (str == "locked") { 
      exits[i] = true; 
     } else if (str == "unlocked") { 
      exits[i] = false; 
     } 
    } 
    return 0; 
};