我的程序返回錯誤「矢量下標超出範圍」。

Question

我不確定哪個向量導致錯誤或問題來自何處。我試圖從一個文件輸入名字和生日，並將它們設置爲向量中的一部分。該文件是：

Mark,12/21/1992 
Jay,9/29/1974 
Amy Lynn,3/17/2010 
Bill,12/18/1985 
Julie,7/10/1980 
Debbie,5/21/1976 
Paul,1/3/2001 
Ian,2/29/1980 
Josh,10/31/2003 
Karen,8/24/2011 

我甚至不知道如果我的代碼完成這個，因爲錯誤。我試圖閱讀更多的stringstream，但我不明白如何正確實現它。所提及的日期類可以在必要時提供，但時間很長。任何有關改進方案的意見以及爲什麼會發生這個問題，我們都非常感謝。 這裏是我的代碼：再次

#include <iostream> 
#include <string> 
#include <fstream> 
#include <vector> 
#include "c://cpp/classes/Date.cpp" 
using namespace std; 

struct person { 
    vector<string> name; // One name string vector 
    vector<Date> birthdate; // One birthdate vector 
    vector<Date> birthday; // birthday vector 
}; 

int main() { 
    string input, input2; // Two string inputs 
    const int PEOPLE_NUM = 10; // Amount of people 

    vector<person> People(PEOPLE_NUM); // Define vector called People with 10 positions 
    string test; 
    ifstream inputFile("C:/Users/Taaha/Documents/CMSC226/Project 3/Names.txt", ios::in); 
    for (int i = 0; i < PEOPLE_NUM; i++) { 
     getline(inputFile, input, ','); // input the line, stop when a comma 
     People[i].name[i] = input; // Add input into the vector 
     getline(inputFile, input2, ','); 
     People[i].birthdate[i] = input2; 
     cout << i; 
    } 
    inputFile.close(); // close file 

    Date birthday; 
    for (int i = 0; i < PEOPLE_NUM; i++) { 
     Date birthday(People[i].birthday[i].getDay(), People[i].birthday[i].getMonth(), Date().getYear()); 
     People[i].birthday[i] = birthday; 
    } // Not finished yet, but turns birthdate into birthday 
    return 0; 
} 

感謝：]

Answer 1

當People[i].name[i] = input;在for循環，People[i].name仍然是一個空載體，在其上調用operator[]將UB。你可能會提前resize，或使用push_back。

for (int i = 0; i < PEOPLE_NUM; i++) { 
    getline(inputFile, input, ','); 
    People[i].name[i] = input;  // People[i].name is still empty here 
    getline(inputFile, input2, ','); 
    People[i].birthdate[i] = input2; // People[i].birthdate is still empty here 
    cout << i; 
} 

您可以使用push_back，比如，

for (int i = 0; i < PEOPLE_NUM; i++) { 
    getline(inputFile, input, ','); 
    People[i].name.push_back(input); 
    //   ~~~~~~~~~~ 
    getline(inputFile, input2, ','); 
    People[i].birthdate.push_back(input2); 
    //     ~~~~~~~~~~ 
    cout << i; 
} 

而且它同另一個for循環。

for (int i = 0; i < PEOPLE_NUM; i++) { 
    Date birthday(People[i].birthdate[i].getDay(), People[i].birthdate[i].getMonth(), Date().getYear()); // typo of birthdate? 
    //      ~~~~~~~~~      ~~~~~~~~~ 
    People[i].birthday.push_back(birthday); 
    //     ~~~~~~~~~~ 
} // Not finished yet, but turns birthdate into birthday