Clarification required regarding Arrays, Vectors and Maps in usage of a C++ Application - c++

Question

I want to know the right algorithm and a container class for my application. I am trying to build one Client-Server communication system where the Server contains group of files (.txt). The file structure (prototype) is like:
A|B|C|D....|Z$(some integer value)#(some integer value). Again the contents of A to Z are a1_a2_a3_a4......aN|b1_b2_b3_b4......bN|......|z1_z2_z3_z4.....zN. So what I wanted to do is when Server application has started, it has to load these files one-by-one and save the contents of each file in a Container class and again the contents of the file into particular variables based on the delimiters i.e.
for (int i=0; i< (Number of files); i++)
{
1) Load the file[0] in Container class[0];
2) Read the Container class[0] search for occurences of delimiters "_" and "|"
3) Till next "|" occurs, save the value occurred at "_" to an array or variable (save it in a buffer)
4) Do this till the file length completes or reaches EOF
5) Next read the second file, save it in Container class[1] and follow the steps as in 2),3) and 4)
}
I want to know if Vector or Map suits my requirement? As I need to search for occurrences of delimiters and push_back them and access while necessity comes.
Can I read whole single file as block and manipulate with the buffer or while file read only using seekg I can push the values to stack? One which will be better and easier to implement? What are the possibilities of using regex?

Answer 1

According to the format of input, and its size, I'd suggest doing something along these lines for reading and parsing the input:
void ParseOneFile (std::istream & inp)
{
std::vector<std::vector<std::string>> data;
int some_int_1 = 0, some_int_2 = 0;
std::string temp;
data.push_back ({});
while (0 == 0)
{
int c = inp.get();
if ('$' == c)
{
data.back().emplace_back (std::move(temp));
break;
}
else if ('|' == c)
{
data.back().emplace_back (std::move(temp));
data.push_back ({});
}
else if ('_' == c)
data.back().emplace_back (std::move(temp));
else
temp += char(c);
}
char sharp;
inp >> some_int_1 >> sharp >> some_int_2;
assert ('#' == sharp);
// Here, you have your data and your two integers...
}
The above function does not return the information it extracts, so you will want to change that. But it does read one of your files into a vector of vector of strings called data and two integers (some_int_1 and some_int_2.) It uses C++11 and does this reading and parsing quite efficiently, both in terms of processing and memory.
And, the above code does not check for any errors and inconsistent formatting in the input file.
Now, for your data structure problem. Since I have no idea about the nature of your data, I can't say for sure. All I can say is that a two-dimensional array and two integers on the side feels like a natural fit for this data. Since you have several files, you can store them all in another dimension of vector (or perhaps in a map, mapping a file name to a data structure like the following:
struct OneFile
{
vector<vector<string>> data;
int i1, i2;
};
vector<OneFile> all_files;
// or...
// map<string, OneFile> all_files;
The above function would fill one instance of the OneFile struct above.
As an example, all_files[0].data[0][0] will be a string referring to data item A0 in the first file, and all_files[7].data[25][3] will be another string referring to data item Z3 in the 8th file.