Implementación de mapas multidimensionales en C++
Multidimensional mapa Los s se utilizan cuando queremos asignar un valor a una combinación de claves. La clave puede ser de cualquier tipo de datos, incluidos aquellos definidos por el usuario. Los mapas multidimensionales son mapas anidados; es decir, asignan una clave a otro mapa, que a su vez almacena combinaciones de valores clave con los valores asignados correspondientes.
Sintaxis:
// Creating a two-dimensional map: map object; // Creating an N-dimensional map: map>objeto;
Ejemplo 1:
// C++14 code to implement two-dimensional map> > #include> using> namespace> std;> > int> main()> {> > > // Two-dimensional key> > map <> int> , map <> int> ,> int> >> metro;> > > // For accessing outer map> > map <> int> , map <> int> ,> int> >>::iterador itr;> > > // For accessing inner map> > map <> int> ,> int> >::iterador ptr;> > > for> (> int> i = 0; i <2; i++) {> > for> (> int> j = 0; j <2; j++) {> > m[i][j] = i + j;> > }> > }> > > for> (> int> i = 0; i <2; i++) {> > for> (> int> j = 0; j <2; j++) {> > > // Accessing through array subscript> > cout < <> 'First key is '> < < i> > < <> ' And second key is '> < < j> > < <> ' And value is '> < < m[i][j] < < endl;> > }> > }> > > cout < <> '
Now accessing map though iterator
'> ;> > > for> (itr = m.begin(); itr != m.end(); itr++) {> > > for> (ptr = itr->segundo.begin(); ptr != itr->segundo.end(); ptr++) {> > cout < <> 'First key is '> < < ' And second key is ' < < ' And value is ' } } }> |
Producción:
First key is 0 And second key is 0 And value is 0 First key is 0 And second key is 1 And value is 1 First key is 1 And second key is 0 And value is 1 First key is 1 And second key is 1 And value is 2 Now accessing map though iterator First key is 0 And second key is 0 And value is 0 First key is 0 And second key is 1 And value is 1 First key is 1 And second key is 0 And value is 1 First key is 1 And second key is 1 And value is 2
Ejemplo 2:
// C++14 code to implement two-dimensional map> // and inserting value through insert()> > #include> using> namespace> std;> > int> main()> {> > > // First key type is a string> > mapint, int>> metro; mapint, int>>::iterador itr; mapa |
Producción:
First key is Geek And second key is 1 And value is 10 First key is Geek And second key is 2 And value is 20 First key is Noob And second key is 0 And value is 5
