C++ :: How To Access Elements In A List
Oct 18, 2013I've been looking through containers in the reference section and I can't figure out how to access (i.e. READ) elements in a list...
View 2 RepliesI've been looking through containers in the reference section and I can't figure out how to access (i.e. READ) elements in a list...
View 2 RepliesI used to use map to access elements. map has a good feature that it sort the element automatically. Now I need a map which can access element through multiple key values. So I choosed boost::multi_index_container. I defined a container as follows.
struct elem {
int a,b;
elem(int aa,int bb):a(aa),b(bb) {}
};
typedef multi_index_container <
[Code] ....
What I am wondering is whether boost::multi_index_container can sort elements automatically. Specifically, are all elements extracted through iterator from begin to end shown below having b values between 2 and 100?
test t;
test::iterator begin = t.lower_bound(make_tuple(1,2));
test::iterator end = t.upper_bound(make_tuple(1,100));
am trying to create a program that asks the user personal questions.
std::vector<std::string> name, age, favsinger;
std::cout << "Hello, what is your Name Age Favorite_Singer? ";
std::cin << name; //i want to store the user's info along with the sibling's
[Code]....
I was writing generic class Array (based on counting access to elements)and i got compiling error I cannot even understand (in vs2012).
Code: [URL] ....
Error: [URL] ....
how would i access the list created,i should be able to access the list from all other class, adding to it update ect ect.
class test2
{
public string FirstName{ set; get; }
public string LastName { set; get; }
public string Location{ set; get; }
private List<test2> myList = new List<test2>();
public override string ToString()
[code]....
now in a seperate class how would i view the item (print in console) and edit 'mike' location to XYZ.
I have a problem like this: I do not know how to count the number of elements in a list of lists. I have the following list of list.
#define VAR(V, init) __typeof(init) V=(init)
#define FOR_EACH(I,C) for(VAR(I, (C).begin()), ite = (C).end();
(I) != ite;
++(I))
std::vector<std::vector<GLdouble> > contours;
[Code] ....
I do not know how to write the part indicated in Bold that represents the number of elements of contour. As seen from the code used for the tesselation OpenGL.
How can i look into the element that are pushed into the list. Something like listPointer[0].heapPointer,50
class CA{
public:
CA(void);
[Code].....
I am given an array with n elements but need to write a function where it returns n-1 elements. Do I need a loop for this? Or must I write a prototype...
Here is what I have thus far:
//given array with 5 elements function must return value 4 elements since -1 is a special character length of list is finite
#include <iostream>
using namespace std;
int main () {
int array [] = {1, 4, -1, 3, 2};
cout << "The array has " <<sizeof (array)/ sizeof (int)<< " elements"<< endl;
return 0;
}
#include<stdio.h>
#include<iostream.h>
struct node {
int info;
struct node *next;
[Code] ....
I am getting runtime error in some cases. Sometimes the last input is printed. How to correct the code and display all elements in the linked list.
This code works:
//void Fighter::LoadAnimation(...){
std::list<SCML_SFML::Entity*> entities;
for(std::map<int, SCML::Data::Entity*>::iterator e = data.entities.begin(); e != data.entities.end(); e++) {
SCML_SFML::Entity* entity = new SCML_SFML::Entity(&data, e->first);
entity->setFileSystem(&fs);
entity->setScreen(&window);
entities.push_back(entity);//problem line
}
}
But if i change entities to a member variable, std::list<SCML_SFML::Entity*> Fighter::m_entities, it does not. Instead i get a write access violation when i try to push_back(entity). i need it to be a member variable because i need to use it in other member functions.
Code:
#include<stdio.h>
#include<stdlib.h>
struct node{
int data;
struct node *next;
[Code] .....
Why isn't this bubble sort working?
void LList :: bubbleSort (LList A, int n){
Node *temp;
temp = Head;
int hold;
for (int pass = 1; pass <= n-1; pass++) // number of passes needed for bubblesort is the number of elements-1 {
for (int c = 0; c < n-pass; c++)//only runs for unsorted elements
[Code] ....
It is passed the LList, and the number of items in the list...
I am trying to query an Informix database using a List<T> collection's elements as variables. I can build the list and connect to the database, but I am unsure how to iterate through the list and query the database for each item in the collection.
My list is of type string, and contains Order Numbers. I want to query item information for each order number in the list.
I'm doing a homework aasignment on templates, and i have to build a list. The problem starts when i am trying to add elements to the list. For instance if i chose to add 5 different elements (1,2,3,4,5) the output will be (5,5,5,5,5).
Code:
void add_back(T t){
Node* tmp = new Node;
tmp -> m_data = &t;
if(m_head == NULL) {
[Code] ....
I am getting an Unhandled exception at 0x00CB569E in AusitnHorton_Chapter17_7.exe: 0xC0000005: Access violation reading location 0xCCCCCCCC.
And, It puts a little yellow arrow at this line:
cout << nodepointer->value << " ";//print current node
when I try to run this program.
//Program:Make a ListNode and simple linked list class. Test the linked list class by adding varous numbers to the list and then test for membership. Then include a search function that returns the position of x on the list, if not found return -1.
#include <iostream>
#include <iomanip>
#include <string>
#include <cmath>
#include <cstring>
#include <fstream>
#include <cctype>
using namespace std;
class LinkedList
[Code] ....
I need to make singly and doubly linked list classes that can insert elements. Once the lists are created, I need to order the linked list elements according to a certain pattern.
order2 pattern:
input: 0 1 2 3 4 5 6 7
output: 1 0 3 2 5 4 7 6
order3 pattern:
input: 0 1 2 3 4 5 6 7 8 9 10 11
output: 2 1 0 5 4 3 8 7 6 11 10 9
sequence order pattern:
input: 0 1 2 3 4 5 6 7 8 9 10 11 12 13
output: 1 0 4 3 2 8 7 6 5 13 12 11 10 9
reverse pattern:
input: 0 1 2 3 4 5 6 7 8 9
output: 9 8 7 6 5 4 3 2 1 0
My instructor has given the description of the required classes in a file interfaces01.h as:
#pragma once
#include <cstdlib>
struct ISingleNode {
ISingleNode() {}
virtual ~ISingleNode() {}
virtual void setValue(int value) = 0;
virtual int getValue() = 0;
[Code] ....
However when I am compiling these files in vs 2013 I am getting the error: cannot open include file Singlenode.h,Singlelist.h.
Also I am not too sure about the sorting and reverse logic. How can I implement these logics.
I'm a little confused by my programming assignment this week. I've been working at it Wednesday and I've made progress but I'm still confused as to how I'm supposed to do this. The class I made is called Stack, and it's derived from a template class called StackADT. We also utilize a class called unorderedLinkedList, which is derived from a class called linkedList.
We're supposed to implement all of the virtual functions from stackADT in the Stack class. The Stack data is stored in a an unorderedLinkedList, so what I'm confused by is how to implement a few of the Stack functions because there are no functions in unorderedLinkedList which we could call to manipulate the data.
As you can see from my attached code, I'm really confused by how I'm supposed to implement the pop() and top() functions, and I also think my initializeList() function is wrong. We don't have any similar functions in unorderedLinkedList to call, so I'm at a loss of how i'd access my unorderedLinkedList. My initial thought was to call the similar functions in the class that unorderedLinkedList was derived from, linkedList, but I'm unsure of this is what we're supposed to do, or if theres actually a way to access my unorderedLinkedList without having to use the functions from the base class.
NOTE: We're not allowed to modify stackADT, unorderedLinkedList, and linkedList.
Stack.h
#include "stackADT.h"
#include "unorderedLinkedList.h"
template<class Type>
class Stack: public stackADT<Type>{
template <class T>
struct nodeType
{
T info;
nodeType<T> *link;
[Code]...
I'm trying to write a function that takes two linked lists and creates a third one with only the common elements.
It assumes the first list (the caller) has no dups, but it doesn't seem to be working. The program doesn't crash, it just hangs when it is supposed to display L3 (the third list)..everything else runs and is displayed fine.
template <typename T>
LList <T> LList <T>:: common (LList <T> &B)//common fct
{
Node <T> *hunter1 = Head;
[Code]......
if we don't provide the acces modifiers for base class and we need to manipulate the private data of base class in derived class. Is there anyway to acces the private data members? Here's a coding example
class A {
private :
int a;
};
class B : public class A {
public :
void displayA() { cout<<a<<endl; }
};
how i can acces the a of base class A in derived class B without acces modifiers.
I create a list of vectors (a vector of n vectors of m elements).
std::vector <std::vector <int> > vsFA (n, std::vector<int>(n));
How I assign values? I try below, but not worked
void armazenaFA( std::vector <int> &vFA) // this function only knows about vFA
{ vsFA[n] [m]= simTime().dbl();
OR
vsFA[n].push_back(simTime().dbl());
}
From HP / Microsoft (Visual Studio C++) <list>:
Code:
struct _Node
{ // list node
_Genptr _Next; // successor node, or first element if head
_Genptr _Prev; // predecessor node, or last element if head
_Ty _Myval; // the stored value, unused if head
};
The stored value is wasted space for the list head. Is there any advantage to implementing list using the same structure for a list head and node?
Code:
// Write a function called insertEntry() to insert a new entry into a linked list.
Have the procedure take as arguments a pointer to the list entry to be inserted (of type struct entry as defined in this chapter), and a pointer to an element in the list after which the new entry is to be inserted.
// The function dveloped in exercise 2 only inserts an element after an existing element in the list, thereby prenting you from inserting a new entry at the front of the list.
(Hint: Think about setting up a special structure to point to the beginning of the list.)
#include <stdio.h
struct entry1 {
int value;
struct entry1 *next;
};
[code]...
This is a working version of the exercise, but I don't think I'm doing what's asked. I was able to add an element to the beginning of the list using an if statement, not creating a special structure that points to the beginning of the list. How would I go about creating a special structure that points to the beginning of the list to add a new element at the beginning of the list?
I'm trying to display a list of MSMQ messages in a list box based on a drop-down list holding the environment.So i've setup the binding and i know that the list loads but nothing shows up in the list? I should be setting like a display member or something but i'm not entirely sure
const String msmqAccelaDev = "FormatName:DIRECT=OS:tcc-intsrvTCCIntegration.MSMQ.Service.Dev/TCCMessagingService.svc";
const String msmqAccelaProd = "FormatName:DIRECT=OS:tcc-intsrvTCCMSMQFail";
const String msmqAccelaTest = "FormatName:DIRECT=OS:tcc-intsrvTCCIntegration.MSMQ.Service.Test/TCCMessagingService.svc";
String currentQueue = "";
private void environmentChange()
[Code]...
I'm trying to get unique elements from a set but it prints for each item all the rest, for example if i have 3 items in a set it will print 6 instead of 3. I use this code:
for (set<string>::iterator i = mails.begin(); i != mails.end(); ++i) {
cout << *i << endl;
}
Is there any way to print just the unique items from a set ?
The set contains:
1
2
3
But it will print
1
2
3
2
3
3
I'm working on a linked list and was wondering how this looks to everybody else for a deleteList function.
void deleteList(Node* head)
{
Node* iterator = head;
while (iterator != 0)
[code].....
Code:
#include <iostream>
using namespace std;
void f();
extern int x;
int main() {
[Code] .....
x is declared outside the functions and defined inside main(). Then why this code produces a compile error?
x is already declared so it can be used in f(); and when I call f(), x is already defined. Then why can't f() sets the value of x (in main) to 10?