Let's say we have a custom Vector class and I need to know which of the following is considered to be more efficient and why of course.
Vector Vector::operator+(const Vector &b) const {
return Vector(x+b.x,y+b.y);
}
Vector Vector::operator+(const Vector &b) const {
Vector tmp(x+b.x,y+b.y);
return tmp;
}
I'm working on a code for ascertaining the minimum penalty of an assignment problem. The basic complication of my code is this: I have a vector of objects of a custom struct. The struct has a member, which is an integer. I need to keep the vector sorted according to that member, even when objects are added to or deleted from the vector. To illustrate the problem, I'll give an example.
Code:
typedef struct examplestruct{int i;
char c;
...} es;
int function(void)
{vector<es> ObjectTable;
//insert an object so that the vector remains sorted according to i
insertobject( newobject, &ObjectTable);
//deleting the top element of the vector
deleteobject(&ObjectTable);
return 0;}
I have tried to do it using bubblesort. But it's too slow. How to make a heap out of it.
The detailed premises of the problem is this: There are a number of jobs, and with each job a completion time and a cost coefficient. We are to ascertain the optimal sequence of jobs for which the penalty is minimum. Now, suppose we are given jobs A, B, C, D and E. We find out the lower bound of penalties for all the jobs.
Suppose we find B has the lowest penalty. Then we find out the lower bound of penalties for BA, BC, BD and BE. We continue this until we have the best value and a complete sequence. The way I have implemented this in a code: I have created two structs. One is Job, with the completion time and cost coefficient as members. The other is Node. Nodes have a Job Array and a Penalty as members. Now, we have a vector of Nodes which we need to keep sorted according to the penalty. We need to insert new Nodes and delete the expanded Nodes.
I have included my code. The pushInTable function inserts the new Nodes in a sorted vector. But it slows down remarkably when we give more than 20 jobs as input.
I am trying to use std::sort to sort a vector of complex objects using a custom function. However, it keeps erroring "Unresolved overloaded function type".
encounter::encounter(){
// ... cut
std::sort (allpeople.begin(), allpeople.end(), sortByInit);}
bool encounter::sortByInit (character& a, character& b) {
if (a.getinit () == b.getinit ()) {
[Code] ....
When we want to use custom classes for the STL set data structure, how to do it?
I look around and see people passing comparators, overloading operator(), and also overloading operator< in the class itself.
Which one's the idiomatic c++ way?
I am currently working on a custom "Array" class for a project, and I have run into an error I don't quite understand the source of. The relevant code is as follows:
template<typename T> class Array {
private:
T errValCopy;
public:
T __errVal__;
uint16 __size__;
T* __ptr__;
Array(const T& errorValue);
[Code] ....
When I try to run the following code:
Array<Array<int>> a(Array<int>(-1));
The error log tells me there is no appropriate default constructor available. If I understand it correctly, "default constructor" refers to the constructor which lets you just write Array<int> a; instead of Array<int> a(...);, but I can't see where in the code such a situation occurs...
I have made a custom class matrices class which allows me to add, multiply, subtract (etc.) matrices. I have the following method for multiplication but I get an error that says
'invalid use of 'this' outside of a non-static member function'
How can I refer to the current instance without getting this error.
void operator *(Matrices& matrix2) {
this.multiplyMatrix(matrix2);
}
I attempted to create a dynamic array class for use in my engine (due to problems regarding a dll-interface with the standard library), so I tried at making a standard-compatible allocator template class first. After I "finished" that, I went on to work on the dynamic array class itself.So I finish the dynamic array class, and test it with the standard allocator. It works perfectly, but when I test it with my custom allocator class, it fails terribly.
To make sure it wasn't my DynamicArray class that was causing issues, I tried using the custom allocator on the std::vector class template, and it didn't work either. IMy DynamicArray class code:
// Represents a dynamic array, similar to the standard library's "vector" class.
template<typename T, typename A>
class DynamicArray
{
public:
DynamicArray() :
data(nullptr),
elements(0),
capacity(0)
[code].....
The "Request" and "Free" functions are my engine's equivalent of malloc and free (or new and delete). I allocate a large buffer (16 mb), and through those functions I distribute the memory to where it's needed.
Right now I have code
#include <iostream>
using namespace std;
class Rectangle {
private:
double width;
double length;
[Code] .....
it gives error ...
I have a class like this:
#include <string>
using namespace std;
//-----------------------------------------------
class Prenumeratorius {
private:
string pavarde;
string adresas;
string leidinioKodas;
[code]....
bunch of variables, constructor, setter and getter.And I have this class:
#include <vector>
class Leidinys {
private:
string kodas;
string pavadinimas;
double vienetoKaina;
[code]....
in to my "Leidinys.h" header file, I get a build error, I tried to remove same includes in both files, that didn't worked.
If I have an array of some class, and that class has const members, is there some way I can call a custom constructor on elements of the array?
I can't seem to reinitialize an element in foos in the example below. A thread on stack overflow mentioned the copy constructor show allow it, but I get "no match for call to '(Foo) (Foo&)'" when I try it.
Code:
class Foo {
public:
Foo();
Foo(int x, int y);
[Code] .....
I need to create a class vector as a template and define operations on vectors.
And this is what I made.
#include<iostream>
using namespace std;
template<class T>
[Code].....
im passing a vector of a class to a function of another class. But i cant access the data on the classes inside the vector.
Something like that:
class CDummy{
...
public:
string m_name;
[Code].....
Im creating the vector on main() and using push_back with a pointer to an initialized CDummy instance
I was trying to implement own vector class and wrote some code. Below is the code.
Code: #include<iostream>
#include<vector>
using namespace std;
template <typename T> class MyVector
{
T *mem;
int m_size,final_size;
public:
MyVector() : final_size(1),m_size(4)
{
[code].....
I have question on this function.
Code: myVecPush_back(T t){}
Here I was able to put elements upto any number of time, but I have allocated memory to only 4 elements in T *mem.
My question, why the program is not crashing when I tried to put elements more that 4?
Is since the variable is of type Template? Any specific reason for this?
First this is my code:
#include <iostream>
#include <vector>
#include <cstdlib>
[Code].....
the blacked content got problems: the error messages are the throat_t::P or throat_t::T is inaccessible.
I have a settings class and a settingItem class. The settings class has a vector of settingItems. The vector is not working:
error C2065: 'settingItem' : undeclared identifier
error C2923: 'std::vector' : 'settingItem' is not a valid template type argument for parameter '_Ty'
with code line:
vector<settingItem> settings;
Okay so I have a class Student, which takes a number and a vector as a parameter for the constructor. Everything works well, until I output the values of the vector for every instance. The problem is that the same vector is being shared with EVERY instance I create, but I want it to be unique for every single one!
//Student.h
#ifndef __Grade_calculator__Student__
#define __Grade_calculator__Student__
#include <iostream>
[Code].....
So I'm trying to store class objects in a vector:
#include <iostream>
#include <fstream>
#include <sstream>
#include <string>
[Code]....
1. Am I storing it correctly?
2. How would I access the stored data, say, if I wanted to compare it to other stored data or COUT it?
What I want to do with the below code is to construct the vector containing 'Ability' objects in the class 'Card'. I have searched for the solution in the past, and have been unsuccessful, mainly because the vector contains child classes of the parent class 'Ability'. The below code is a snippet of the larger program that I am working on, and should compile:
main:
Code:
#include <cstdlib>
#include <iostream>
#include <vector>
#include <string>
using namespace std;
#ifndef _abilities_h_
[Code] ....
As you can see, in the class 'Card' I have a pretty large constructor. Up to this point, however, I have failed in my attempts to construct the abilities vector, because it contains those child classes.
Input file:
Course Of Sales.csv
Time,Price ($),Volume,Value ($),Condition
10/10/2013 04:57:27 PM,5.81,5000,29050.00,LT XT
10/10/2013 04:48:05 PM,5.81,62728,364449.68,SX XT
10/10/2013 04:10:33 PM,.00,0,.00,
How to read the csv file with my own vector class. I already have date.h,date.cpp,time.h,time.cpp
How to do the maintest and how to create the vector class
I need to show Date, highest price and Start time(s) of the highest share price
For a beginners C++ lab, I have a base class Employee and two derived classes HourlyEmployee and SalaryEmployee. In main, I have a vector defined as vector <Employee *> VEmp; It's then passed to a function to get the input, which works fine. But what I'm struggling with is another function with the header "printList(const vector <Employee *> & Ve)". It's supposed to loop through the vector and call the appropriate printPay function, which is a seperate print function inside each derived class. How do I loop through the vector and print it out? I was trying to do a for loop and something like "Ve[i].printPay();", but that doesn't work. So how would I do it?
Here's some snippets of the relevant code.
class Employee {
....
virtual void printPay() = 0;
};
class HourlyEmployee : public Employee {
[Code] ....
I have to create a class to represent a 2 dimensional vector. I need to include certain member functions such as a function to find magnitude of the vector, and one to find the dot product of that vector with another vector, and several others too. That's all fine. A stipulation of the problem is that I must include a constructor which can take cartesian form of the vector and a constructor which can take polar form of vector. Since this involves overloading the constructor the best solution I have come up with is to create the object with either doubles or floats so that the compiler can choose the correct constructor. This seems like a really bad idea. Is there a way I can get the compiler to choose the correct constructor without doing it using the precision? Here is a sample of my header file, there are many more member functions
class Vector{
public:
Vector(double x, double y, double v, double w){
myArray[0]=x;
myArray[1]=y;
additionalArray[0]=v;
additionalArray[1]=w;
[Code] .....
In my .cpp file the object is created with either four doubles or four floats depending on which constructor I want to implement. There must be a better way. Additional Array is created for use in member function which require calculations with a second 2d vector.
I need to create a vector of pointers and hold the book objects in it. then i have a virtual function in my books which is a pure virtual in LibraryItems. When i try to add the books object in my code, i understand that since the scope runs out there is no object that is added. so when i run print it gives me an error.
#include<iostream>
#include "books.h"
#include "library.h"
#include <vector>
using namespace std;
int main(int argc, char * argv[]) {
vector<LibraryItems* >libraryInfo;
[Code] .....
I get a problem with the vector as a private class member: When I did't initialize the vector in constructor(which means the size of the vector would be 0), I used a class function to add two elements to the vector and it worked (because I added a "printf" to output the size of the vector and the elements within that function). However, when I used another class function to visit that vector, no element was in and the size became 0.
Then I tried to add two elements to the vector during the construction, and it turned out that these two elements could be stored in the vector while other elements added through class functions could not.
I guess there may be some problems on the scope of the function. But I feel the class member should not be effected by the scope of the class function.
How I can use class functions in a vector. I have 2 classes:
Gamemode class
bullets class
Inside the Gamemode class I declared: vector<bullets> Bullet and bullets * b.
If the user presses the shoot button a new bullets class will be added to the Bullet vector:
b = new bullets;
Bullet.push_back(b)
Bow I'd like to check all objects in the Bullet vector for the collision() function inside the bullets class.
I already set up a for loop which counts from 0 to the end of the vector:
for( int i=0;i<Bullet.size;i++)
{
}
My idea was to do something like:
if(Bullet[i].collision()) then erase Bullet[i]
But that doesn't work...
I'm having the same problem : [URL] .....
Though, my vector isn't one of int, it is a vector of objects from another class and NetBeans won't compile it.
#include <cstdlib>
#include<vector>
#include <string>
#include<iostream>
using namespace std;
class estoque{
[Code] .....
I want to make a class, named generation, having a vector<chromosome> type data member.
chromosome is also class name.
chromosome has a 'route' as data member, which type is class TArrayI defined in ROOT package.
the size of route is to be fixed according to parameters of generation class object.
class chromosome{
public: chromosome(){;}
....
protected:
TArrayI route;
};
class generation{
public: generation(int PopSize=300, int numCity = 36){
.........
}
vector<chromosome> Population;
};
I want each element, chromosome of Population, to have a numCity size of route.