Отправлено: 15.07.14 20:16. Заголовок: 2D vector to 3D

i have a 2D vector that contain data like

[0][1] = 11
[0][2] = 10
[0][3] = 12

[1][1] = 54
[1][2] = 65
[1][3] = 46

[2][1] = 524
[2][2] = 655
[2][3] = 446


i like to add this 2D vector data to a 3D vector how can i do this in a perfect way

 Отправлено: 15.07.14 21:17. Заголовок: Having one two-dimen..

Having one two-dimensional array you can create a 3D vector only with one element. For example

 
 #include <iostream> 
 #include <vector> 
 #include <iterator> 
 #include <algorithm> 
  
 int main() 
 { 
 	const size_t N = 3; 
 	int a[N][N] =  
 	{ 
 		{  11,  10,  12 }, 
 		{  54,  65,  46 }, 
 		{ 524, 655, 446 } 
 	}; 
  
 	std::vector<std::vector<std::vector<int>>> v( 1 ); 
  
 	std::transform( std::begin( a ), std::end( a ), std::back_inserter( v[0] ), 
 		[]( const int ( &row )[N] )  
 		{  
 			return std::vector<int>( std::begin( row ), std::end( row ) ); 
 		} ); 
  
 	std::for_each( v[0].begin(), v[0].end(), 
 		[]( const std::vector<int> &v1 ) 
 		{ 
 			std::copy( v1.begin(), v1.end(), std::ostream_iterator<int>( std::cout, " " ) ); 
 			std::cout << std::endl; 
 		} ); 
  
 	/* Or using range-based for statements  
 	for ( const std::vector<int> &v1 : v[0] ) 
 	{ 
 		for ( int x : v1 ) std::cout << x << ' '; 
 		std::cout << std::endl; 
 	} 
 	*/ 
 } 
 

The output is

 
 11 10 12 
 54 65 46 
 524 655 446 
 

If the 2D vector is not an array but in turn an object of type std::vector<std::vector<int>> then you can simply use push_back method.. For example

 
 std::vector<std::vector<std::vector<int>>> v; 
 std::vector<std::vector<int>> v1; 
  
 //... some code of filling v1 
  
 v.push_back( v1 ); 
 

 Отправлено: 16.07.14 07:47. Заголовок: how can i control in..

how can i control index of 3d vector to pushback 2D vector to it i don't get complete idea of 3D vector.
for example if we creating a 2D array we use two for loop to control index (column index & row index )
if i use your last method to pushback 2D vector. in 3D vector --> [0][0][1] , [0][0][2] i like to manipulate other index to how can i do that

 Отправлено: 16.07.14 20:23. Заголовок: I have not understoo..

I have not understood what is unclear for you. You can use vectors as arrays accessing their elements by indices. 3D vector contains 2D vectors. So for example if v is 3D vector then v[0] provides access to the first 2D vector, v[1] provides access to the next 2D vector.

 Отправлено: 17.07.14 08:10. Заголовок: i ask you how i wri..

i ask you how i write for loop for that to access [0][0][1],[0][1][1],[1][1][1] . i got it thanks.
is there any better way of doing this please show me .
`
#include <iostream>
#include <vector>
#include <cstdlib>
using namespace std;


int main ()
{
vector < vector < vector<int> > > tube;
for(int i = 0; i < 2; i++)
{
vector < vector < int > > w;
tube.push_back( w );
for(int j = 0; j < 4; j++)
{
vector <int> v;
tube[ i ].push_back( v );
for(int k = 0; k < 15; k++)
{
tube[ i ][ j ].push_back( rand());
}
}
}

for (size_t i = 0; i < tube.size(); i++)
for (size_t j = 0; j < tube[ i ].size(); j++)
for (size_t k = 0; k < tube[ i ][ j ].size(); k++)
cout << "tube[" << i << "][" << j << "][" << k << "] = " << tube[ i ][ j ][ k ] << endl;
}
`

 Отправлено: 17.07.14 21:43. Заголовок: In fact that or othe..

In fact that or other way you have to use loops. In C++ 11 I would write the code the following way

 
 #include <iostream> 
 #include <vector> 
 #include <algorithm> 
 #include <cstdlib> 
 #include <ctime> 
  
 int main()  
 { 
 	size_t K = 2; 
 	size_t N = 4; 
 	size_t M = 15; 
 	std::vector<std::vector<std::vector<int>>> v( K ); 
  
 	std::srand( ( unsigned int )std::time( 0 ) ); 
  
 	for ( std::vector<std::vector<int>> &w : v ) 
 	{ 
 		w.assign( N, std::vector<int>( M, 0 ) ); 
 		for ( std::vector<int> &u : w ) 
 		{ 
 			std::generate( u.begin(), u.end(), []{ return std::rand() % 10; } ); 
 		} 
 	} 
 	 
 	for ( const std::vector<std::vector<int>> &w : v ) 
 	{ 
 		for ( const std::vector<int> &u : w ) 
 		{ 
 			for ( int x : u ) std::cout << x << ' '; 
 			std::cout << std::endl; 
 		} 
 		std::cout << std::endl; 
 	} 
  
 	return 0; 
 } 
 

The output is

 
 9 1 5 7 9 8 3 4 9 9 3 6 8 7 6  
 9 0 1 5 9 2 1 1 3 3 4 7 7 2 3  
 2 3 6 8 0 7 6 3 2 7 4 7 3 2 4  
 0 1 4 3 8 3 7 9 6 0 3 1 9 2 5  
  
 4 4 8 3 4 8 0 2 3 4 9 7 3 3 1  
 7 5 4 4 0 2 9 7 1 6 9 6 9 0 8  
 6 4 5 4 7 9 4 8 2 7 4 1 6 8 6  
 7 7 1 1 1 3 5 3 0 6 9 1 5 0 1