C++ Creating a Matrix of Sets - c++

Question

I am trying to create a Matrix of Sets in C++ but I get an error that there is no matching function to call. Here is my code:
supermercat.hh
#ifndef SUPERMERCAT_HH
#define SUPERMERCAT_HH
#include <vector>
#include <iostream>
#include <set>
#include "producte.hh"
using namespace std;
class supermercat
{
private:
vector <vector <set <producte> > > estructura;
public:
// Constructores
supermercat();
//Modificadores
void crear_estructura(int col, int fil);
void repostar_estanteries(producte prod, string lloc);
supermercat.cc
#include "supermercat.hh"
supermercat::supermercat() {}
void supermercat::crear_estructura(int col, int fil)
{
vector <vector <set <producte> > > estructura(col, vector<producte>(fil));
}
void supermercat::repostar_estanteries(producte prod, string lloc)
{
estructura[lloc[0] - 'A'][lloc[1] - 1].insert(prod);
}
Does anyone know what I am doing wrong? I just can't figure it out.
I tried to do it as a matrix of vectors in the past but it as kind of annoying to sort each vector in the matrix (as I need 'productes' to be ordered alphabetically).

Answer 1

I think that the problem is your crear_estructura method implementation. In the base class (supermercat), you have the private member:
vector <vector <set <producte> > > estructura;
In the implementation part, you try to execute following:
vector <vector <set <producte> > > estructura(col, vector<producte>(fil));
and it is not defined elsewhere (to me, this line is a declaration, it does not implement anything).
Also, the input:
vector<producte>(fil)
in previous definition is rather strange. Did you mean to use square brackets, i.e. [] instead of ()? E.g. vector<producte> prods[fill].
As your solution is somewhat tricky, I'd suggest to simplify it a bit. The quick solution is to make a new class estructura (fill in as appropriate):
class estructura
{
private:
vector <vector <set <producte> > > _mestruct;
public:
estructura(int col, vector<producte> fil);
~estructura();
}
and then implement constructor to fit your requirements. After that, use it in the supermercat class like this:
class supermercat
{
private:
estructura structdata;
public:
... (like before)
}
and your supermercat constructor implementation should be like this:
void supermercat::crear_estructura(int col, vector<producte> fil)
{
estructura(col, fil);
}
I hope this will help you a bit to solve the problem.

Answer 2

The problem you have is with the vector initialization, you should use resize() to resize the first dimension and then resize for each item to resize the other dimension of the vector, here is a simple example that does that:
#include <iostream>
#include <vector>
#include <set>
std::vector< std::vector< std::set<int> > > test;
int main()
{
test.resize(100);
// if not c++11 replace with for (i = 0; i < 100; ++i) test[i].resize(100)
for (auto &a: test)
a.resize(100);
test[20][20].insert(1);
test[30][30].insert(1);
test[30][30].insert(2);
std::cout << "(20,20): " << *test[20][20].begin() << std::endl;
std::cout << "(30,30): size " << test[30][30].size() << std::endl;
}
Using this syntax in your "create_estructura" method it should be something like:
void supermercat::crear_estructura(int col, int fil)
{
estructura.resize(col);
for (auto &a: estructura) a.resize(fil);
}
Every item in "estructura" will contain an empty set.