How do I erase an element from std::vector<> by index?
To delete a single element, you could do: Or, to delete more than one element at once:
vector
C++ for each, pulling from vector elements
For next examples assumed that you use C++11. Example with ranged-based for loops: You should use const auto &attack depending on the behavior of makeDamage(). You can use std::for_each from standard library + lambdas: If you are uncomfortable using std::for_each, you can loop over m_attack using iterators: Use m_attack.cbegin() and m_attack.cend() to get const iterators.
How to navigate through a vector using iterators? (C++)
You need to make use of the begin and end method of the vector class, which return the iterator referring to the first and the last element respectively.
Counting the number of elements with the values of x in a vector
You can just use table(): Then you can subset it: Or convert it into a data.frame if you’re more comfortable working with that:
check if a std::vector contains a certain object?
Checking if v contains the element x: Checking if v contains elements (is non-empty):
numpy matrix vector multiplication
Simplest solution Use numpy.dot or a.dot(b). See the documentation here. This occurs because numpy arrays are not matrices, and the standard operations *, +, -, / work element-wise on arrays. Note that while you can use numpy.matrix (as of early 2021) where * will be treated like standard matrix multiplication, numpy.matrix is deprecated and may … Read more
How do I print out the contents of a vector?
If you have a C++11 compiler, I would suggest using a range-based for-loop (see below); or else use an iterator. But you have several options, all of which I will explain in what follows. range-based for-loop (C++11) In C++11 (and later) you can use the new range-based for-loop, which looks like this: The type char … Read more
How to find out if an item is present in a std::vector?
You can use std::find from <algorithm>: This returns a bool (true if present, false otherwise). With your example:
Vector of Vectors to create matrix
As it is, both dimensions of your vector are 0. Instead, initialize the vector as this: This will give you a matrix of dimensions RR * CC with all elements set to 0.
What is the easiest way to initialize a std::vector with hardcoded elements?
One method would be to use the array to initialize the vector