Reading this question, I've decided I need to use something like this:
list<vector<开发者_Go百科;double> > psips;
for a simulation in c++. The question is, what is the simplest (and a reasonably efficient) way of initiating a list like this containing N
vectors with d
zeros in each?
Cheers!
std::list<std::vector<double> > psips(N, std::vector<double>(d));
See #3 here and #2 here.
you can use the stl constructor, and set the default value to zero:
explicit vector ( size_type n, const T& value= T());
explicit list ( size_type n, const T& value = T())
So what you would do is:
vector< double > example( d, 0);
list< vector < double > > your_list(N, example);
And you have a list of N vector and d vector with zeros in it.
std::list<std::vector<double> > psips(100, std::vector<double>(10, 20.0));
Each vector in the list is having 10
elements, each initialized with 20.0
. And total number of such vectors in the list is 100
.
精彩评论