如何在C++中將文本文件傳輸到數組2D？

Question

我如何可以將C++中的文本文件（.txt），以陣列2D，這是我的源代碼

fstream fin('textfile.txt', ios::in); 
int matrix[n][m]; // n is the number of rows and m is the number of columns 
for(int i = 0;i < n; i++){ 
    for(int j = 0; j<m; j++){ 
    fin>>matrix[i][j]; 
    } 
} 

但我怎麼能detemine n和m爲做到這一點，我需要您的幫助和建議請加入我們您的觀點

Answer 1

該解決方案需要C++ 11 +

如果在文件中不適用&男，你必須假設的佈局也是2D

一二三
四五六

警告::未經測試的代碼。

std::stringstream res; 
std::string wordUp; 
std::vector<std::string> str; 

// the matrix, vector of vector of strings. 
std::vector<std::vector<std::string>> matrix; 

fstream fin('textfile.txt', ios::in); 
int lines = 0; 
int words = 0; 

// read the file line by line using `getline` 
for (std::string line; std::getline(fin, line);) { 
    ++lines; 
    // use stringstream to count the number of words (m). 
    res.str(line); // assign line to res. might also need some reset of good(). 
    while (res.good()) { 
    res >> wordUp; 
    str.push_back(wordUp); 
    ++words; 
    } 
    matrix.push_back(str); 
    str.erase(str.begin()); 
} 

Answer 2

所以ü意味着ü要讀取文件和複製內容到char矩陣[] [] ??，你可以使用while循環讀取字符，並通過線每1024個字節（1 KB）分裂，我的意思是這樣做：

#include <fstream.h> 

int main() 
{ 
int n=0, m=0, MAX_LINES=1025, i=0, j=0; 
char character, Matrix[1024][1025]; 
fstream file; 
file.open("file.txt", ios::in); 
while (file.get(character))// loop executes until the get() function is able to read contents or characters from the file 
{ 
Matrix[n][m]=character; // copy the content of character to matrix[n][m], here n is used to work as lines and m as normal arrays. 
m++; // finished copying to matrix[n][m] then m++ else the program will overwrite the contents to the same array. 
If (m>=1024)// if string[n][m] reached the limit which is 1024. 
{ 
Matrix[n][m]='\0'; //termimate that line 
m=0;// start with a new column 
if (n<MAX_LINES)// if n is less than 1024 then 
n++;// write to a next line because m can support only 1024 chars. 
} 
} 
Matrix[n][m]='\0';// this will terminate the whole string not just one line. 
file.close(); 
for (i=0; i<1025; i++) 
{ 
for (j=0; j<=1024 || Matrix[i][j]!='\0'; j++) 
cout<<Matrix[i][j]; 
} 
return 0; 
} 

此代碼將讀取1024×1024個字符，但如果txt文件是小於1024（M）的字符，while循環將退出和Matrix [n]的[M] = '\ 0';語句被執行。

編輯：正如大衛問我寫的整個代碼與主（）對不起兄弟我忘了，代碼中的錯誤是變量n和m初始化到1025和1024，所以程序跳過寫入矩陣作爲矩陣[1024] [1025]不能存儲更多的字符...我認爲這會有所幫助，好的兄弟...