how to build a recursive map ?

[jose luis fernandez diaz]

Hi,

When I want build a tree I define the structure below:

struct node
{
string data;
node *leaf;
node *right;
};


I want to define a map where each element is a map. Something similar to:

map<string, map *> m1;


Any idea ?

Thanks,
Jose Luis.

 

[Karl Heinz Buchegger]

I want to define a map where each element is a map. Something similar to:

map<string, map *> m1;

This is not a map of maps, it is a map of pointers to maps.
Anyway: what is your problem?

lets say you have a map, which maps int to double

map< int, double >

you now want to build a map out of this, such that a string
selects the map which maps int to double.

map< string, map< int, double > >

 

[John Harrison]

Hi,

When I want build a tree I define the structure below:

struct node
{
string data;
node *leaf;
node *right;
};


I want to define a map where each element is a map. Something similar to:

map<string, map *> m1;


Any idea ?

Thanks,
Jose Luis.

Like this

class Recursive
{
public:
...
private:
map<string, Recursive*> m1;
};

john

 

[jose luis fernandez diaz]

This is not a map of maps, it is a map of pointers to maps.
Anyway: what is your problem?

lets say you have a map, which maps int to double

map< int, double >

you now want to build a map out of this, such that a string
selects the map which maps int to double.

map< string, map< int, double > >

I need something like this:

template<class key, class T, . . .>
class map
{
typedef Key key_type;
// typedef T mapped_type;
typedef map *mapped_type;

. . .
}

map<string> m1;
m1["one"] = NULL;
m2["two"] = m1;

but I think that it is not posible.

I tried to simulate it with:

map<string, map<string, map<string ... string> . . . > m_n;

m_1["one"] = "zero";
m_2["two"] = m1["one];
.. . .
m_n["n"] = n_n_1["n-1"];


but this is ugly.

Regards,
Jose Luis.

 

[Dan Cernat]

Hi,

When I want build a tree I define the structure below:

struct node
{
string data;
node *leaf;
node *right;
};


I want to define a map where each element is a map. Something similar to:

map<string, map *> m1;


Any idea ?

Thanks,
Jose Luis.

try

map<string, void*>

and cast the void* to a map<string, void*> internally and so on. you
stop when the pointer is null.

to add elements to such thing:

map<string, void*> leaf1, leaf2;
leaf1["aa"] = 0;
laef2["bb"] = 0;

map<string, void*> node1;
node1["leaf1"] = leaf1;
node1["leaf2"] = leaf2;

dan