Use the std::vector::vector(count, value) constructor that accepts an initial size and a default value: If a value other than zero, say 4 for example, was required to be the default then: I should also mention uniform initialization was introduced in C++11, which permits the initialization of vector, and other containers, using {}:
Because a std::vector has no particular feature regarding inserting elements at the front, unlike some other containers. The functionality provided by each container makes sense for that container. You probably should be using a std::deque, which is explicitly good at inserting at the front and back. Check this diagram out.
Firstly you need to learn the differences between references and pointers and then the difference between pass-by-reference and pass-by-pointer. A function prototype of the form: expects a function call of the type: Whereas, a prototype of the form: expects a function call of the type: Using the same logic, if you wish to pass the vector by reference, … Read more
The error is because of the declaration: The vector contains pointers to mutable ships, but the code passes a pointer to a const ship to push_back. You either need to store const pointers in the vector: Or pass a non const pointer to the push_back: Side note: move the above function to a cpp, move it … Read more
Regardless of how do you index the pushbacks your vector contains 10 elements indexed from 0 (0, 1, …, 9). So in your second loop v[j] is invalid, when j is 10. This will fix the error: In general it’s better to think about indexes as 0 based, so I suggest you change also your first loop to this: Also, to access the elements of a … Read more
In C++, things are passed by value unless you specify otherwise using the &-operator (note that this operator is also used as the ‘address-of’ operator, but in a different context). This is all well documented, but I’ll re-iterate anyway: You can also choose to pass a pointer to a vector (void foo(vector<int> *bar)), but unless you … Read more
There’s a function std::reverse in the algorithm header for this purpose.
Implementation 1 returns the magnitude of the vector that would result from a regular 3D cross product of the input vectors, taking their Z values implicitly as 0 (i.e. treating the 2D space as a plane in the 3D space). The 3D cross product will be perpendicular to that plane, and thus have 0 X … Read more
Your second example does not work if you send the argument by reference. Did you mean That would work, but an easier way is
Your function declaration and definition are not consistent, you want to generate vector from Initialize, you can do: To print vector: Now you call: Don’t forget to change function definition of Initialize, Print to match the new signature I provided above. Also you are redefining a local variable v which shadows function parameter, you just … Read more